MCQ on Friction Clutches, Brakes, Belt Drives and Chain Drives:
Q. Clutch and coupling perform the same action.
A. Both being permanent joints
B. No they are different type of joints
C. Both being temporary joints
D. None of the listed
.
Answer: B
Explanation: Clutch is a temporary joint while coupling is a permanent joint.
Q. Eddy current clutch is a type of friction clutch.
A. Yes
B. No, it is an electromagnetic type clutch
C. It is a mechanical clutch
D. None of the listed
.
Answer: B
Explanation: Eddy current clutch is a type of electromagnetic clutch.
Q. In positive contact clutches, power transmission is achieved by means of friction.
A. Yes
B. It is achieved by shear contact
C. Major part is achieved by friction
D. None of the listed
.
Answer: B
Explanation: Power transmission is achieved by interlocking of jaws or teeth.
Q. The jaw clutches show great amount of slip.
A. Yes
B. Zero slip
C. Used in non-synchronous applications
D. None of the listed
.
Answer: B
Explanation: Jaw clutches do not slip and are used in synchronous applications.
Q. For a new friction lining, uniform wear theory is used.
A. True
B. False
.
Answer: B
Explanation: Uniform pressure theory is used.
Q. A plate clutch consists of 1 pair of contacting surfaces. The inner and outer diameter of the friction disk is Q.0mm and 200mm respectively. The coefficient of friction is 0.2 and permissible intensity of pressure is Q.5N/mm². Assuming uniform wear theory, calculate the operating force in the clutch.
A. 15546N
B. 12344N
C. 23562N
D. 24543N
.
Answer: C
Explanation: P=πpd(D-D./Q.
Q. A plate clutch consists of 1 pair of contacting surfaces. The inner and outer diameter of the friction disk is Q.0mm and 200mm respectively. The coefficient of friction is 0.2 and permissible intensity of pressure is Q.5N/mm². Assuming uniform wear theory, calculate the torque transmitting capacity of the clutch.
A. 4Q.23N-m
B. 35Q.43N-m
C. 33Q.53N-m
D. 39Q.34N-m
.
Answer: B
Explanation: P=πpd(D-D./2 and M=μP(D+D./Q.
Q. A plate clutch consists of 1 pair of contacting surfaces. The inner and outer diameter of the friction disk is Q.0mm and 200mm respectively. The coefficient of friction is 0.2 and permissible intensity of pressure is Q.5N/mm². Assuming uniform wear theory, calculate the power transmitting capacity of the clutch at 80rad/s.
A. 2Q.8kW
B. 3Q.4kW
C. 2Q.2kW
D. 3Q.5kW
.
Answer: A
Explanation: P=πpd(D-D./2 and M=μP(D+D./Q.Power=Mxω.
Q. A plate clutch consists of 1 pair of contacting surfaces. The inner and outer diameter of the friction disk is Q.0mm and 200mm respectively. The coefficient of friction is 0.2 and permissible intensity of pressure is Q.5N/mm². Assuming uniform pressure theory, calculate the operating force in the clutch.
A. 15546N
B. 12344N
C. 23562N
D. 35343N
.
Answer: D
Explanation: P=πp(D²-d²)/Q.
Q. A plate clutch consists of 1 pair of contacting surfaces. The inner and outer diameter of the friction disk is Q.0mm and 200mm respectively. The coefficient of friction is 0.2 and permissible intensity of pressure is Q.5N/mm². Assuming uniform pressure theory, calculate the torque transmitting capacity of the clutch.
A. 4Q.23N-m
B. 54Q.78N-m
C. 56Q.54N-m
D. 67Q.86N-m
.
Answer: B
Explanation: P= πp(D²-d²)/4 and M=μP(Dᵌ-dᵌ)/3(D²-d²).
Q. A plate clutch consists of 1 pair of contacting surfaces. The inner and outer diameter of the friction disk is Q.0mm and 200mm respectively. The coefficient of friction is 0.2 and permissible intensity of pressure is Q.5N/mm². Assuming uniform wear theory, calculate the power transmitting capacity of the clutch at 80rad/s.
A. 27kW
B. 32kW
C. 39kW
D. 44kW
.
Answer: D
Explanation: P= πp(D²-d²)/4 and M=μP(Dᵌ-dᵌ)/3(D²-d²).Power=Mxω.
Q. If number of contacting surfaces are 5, then number of disks required in multi disk clutch are?
A. 4
B. 5
C. 6
D. Can’t be determined
.
Answer: C
Explanation: Disks=Contacting surfaces+Q.
Q. Multi disk clutches are dry clutches.
A. Plasma clutches
B. Wet clutches
C. Yes
D. Depends on the lubrication used
.
Answer: B
Explanation: They are wet clutches as a lot of heat is dissipated due to more contacting surfaces.
Q. In scooters, generally single plate clutches are used.
A. True
B. False
.
Answer: B
Explanation: Multi disk plate clutches which are compact are used.
Q. The coefficient of friction is high in multi disk plate clutch.
A. Yes
B. Coefficient of friction is less
C. Coeffficient of friction is high
D. None of the listed
.
Answer: B
Explanation: In multi disk clutch, due to oil cooling, coefficient of friction decrease.
Q. A cone clutch consists of inner conical surface and outer cylindrical surface.
A. Both cylindrical
B. Both conical
C. Outer conical and inner cylindrical
D. True
.
Answer: B
Explanation: It consists of both inner and outer conical surfaces.
Q. Power is transmitted only by key and friction in the cone clutch.
A. Only by spline
B. By key, spline and friction
C. By friction only
D. By key only
.
Answer: B
Explanation: Power is transmitted via key, friction and spline.
Q. The torque transmitting capacity of cone clutch increases as its semi vertical angle increase.
A. True
B. Decreases
C. Remains constant
D. None of the listed
.
Answer: B
Explanation: Torque transmitted is inversely proportional to the sin of the semi vertical angle.
Q. When semi vertical angle is greater than angle of static friction, clutch results in self-engagement.
A. True
B. False
.
Answer: B
Explanation: Self engagement takes place when semi vertical angle is reduced so low to increase torque capacity that it become smaller than static friction angle.
Q. A cone clutch with a small semi cone angle requires a relatively large force to engage and small force to disengage.
A. True
B. False
.
Answer: B
Explanation: It requires large force to disengage.
Q. A cone clutch transmits 24kW at 490rpm. The coefficient of friction is 0.2 and allowable intensity of pressure is 0.35N/mm². The semi cone angle is 12⁰. The outer diameter is fixed as 3Q.mm.Assuming uniform wear theory; find the maximum torque which is transmitted.
A. 50Q.4N-m
B. 54Q.3N-m
C. 46Q.72N-m
D. 45Q.5N-m
.
Answer: C
Explanation: M=PowerxQ.ᵌx60/2πN.
Q. A cone clutch transmits 24kW at 490rpm. The coefficient of friction is 0.2 and allowable intensity of pressure is 0.35N/mm². The semi cone angle is 12⁰. The outer diameter is fixed as 3Q.mm.Assuming uniform wear theory; find the inner diameter.
A. 275mm
B. 300mm
C. 290mm
D. 280mm
.
Answer: B
Explanation: M=πpμd(D²-d²)/8Sinἀ.
Q. A cone clutch transmits 24kW at 490rpm. The coefficient of friction is 0.2 and allowable intensity of pressure is 0.35N/mm². The semi cone angle is 12⁰. The outer diameter is fixed as 3Q.mm.Assuming uniform wear theory; find the face width of friction lining.
A. None of the listed
B. 4Q.1mm
C. 5Q.2mm
D. 5Q.8mm
.
Answer: B
Explanation: b=D-d/2Sinἀ.
Q. A cone clutch transmits 24kW at 490rpm. The coefficient of friction is 0.2 and allowable intensity of pressure is 0.35N/mm². The semi cone angle is 12⁰. The outer diameter is fixed as 3Q.mm.Assuming uniform wear theory; calculate force required to engage clutch.
A. 354Q.9N
B. 223Q.5N
C. 324Q.5N
D. 435Q.5N
.
Answer: C
Explanation: P=4MSinἀ/μ(D+D..
Q. Centrifugal clutches are not recommended for IC engine applications.
A. True
B. False
.
Answer: B
Explanation: IC engine is not able to start under load ad hence centrifugal clutches are used.
Q. In a centrifugal clutch, when the centrifugal force is slightly more than the spring force, shoe begins to move in a radially inward direction.
A. Radially outwards
B. Radially upwards
C. Radially downwards
D. Radially inwards
.
Answer: A
Explanation: It moves in radially outward direction.
Q. Chain saws, lawnmowers, golf carts etc. never use centrifugal clutches.
A. True
B. No, it is highly used
C. Depends on the load required
D. None of the listed
.
Answer: B
Explanation: The electric motor has time to accelerate to reach the operating speed before it takes the load and hence centrifugal clutches are used.
Q. The centrifugal clutches are used in light duty vehicles and not in heavy duty vehicles.
A. True
B. False
.
Answer: B
Explanation: Centrifugal clutches are used in heavy uty applications as they provide a time delay that is sufficient to permit the prime mover to gain momentum before taking over the load.
Q. Find number of contacting surfaces for a multi disk clutch plate transmitting torque of Q.N-m and inner and outer diameters of friction lining are 70mm and Q.0mm respectively. The operating force is of magnitude 305N and coefficient of friction is 0.Q.
A. 5
B. 2
C. 4
D. 3
.
Answer: C
Explanation: z=4M/μP(D+D..
Q. The energy absorb by brake is always kinetic.
A. No, potential
B. Kinetic or potential
C. Potential
D. Strain Energy
.
Answer: B
Explanation: It can be either kinetic or potential.
Q. Pneumatic brakes are same as electrical brakes.
A. Yes both are concerned with electricity
B. No, one deals with pressure and other with electricity
C. Yes both deals with pressure
D. None of the listed
.
Answer: B
Explanation: Pneumatic brakes are operated by fluid pressure.
Q. Disc brakes are radial brakes.
A. True
B. False
.
Answer: B
Explanation: Disc brakes are axial brakes.
Q. Internal shoe brakes are radial while external shoe brakes are axial brakes.
A. True
B. False
.
Answer: B
Explanation: Both internal and external shoe brakes are radial brakes.
Q. A solid cast iron disk of mass Q.00kg is rotating at 350rpm. Diameter of the disk is 1m and time taken to come to stop the disk by brake is Q.6sec.Calculate energy absorbed by the brake if square of radius of gyration is 0.Q.
A. None of the mentioned
B. 13Q.3kJ
C. 16Q.3kJ
D. 13Q.2kJ
.
Answer: B
Explanation: E=mk²ω²/Q.
Q. A solid cast iron disk of mass Q.00kg is rotating at 350rpm. Diameter of the disk is 1m and time taken to come to stop the disk by brake is Q.6sec.Square of radius of gyration is 0.Q. Calculate the average angular velocity during braking period.
A. Q.45rad/s
B. Q.32rad/s
C. 1Q.32rad/s
D. None of the mentioned
.
Answer: C
Explanation: ω(avg)=[ω()initial+ω(final)]/Q.
Q. A solid cast iron disk of mass Q.00kg is rotating at 350rpm. Diameter of the disk is 1m and time taken to come to stop the disk by brake is Q.6sec.Square of radius of gyration is 0.Q. Calculate the angle through which disk rotated during braking period.
A. 2Q.5rad
B. 2Q.6rad
C. 2Q.3rad
D. 3Q.4rad
.
Answer: C
Explanation: ω(avg)=[ω()initial+ω(final)]/2 and θ=ωt.
Q. A solid cast iron disk of mass Q.00kg is rotating at 350rpm. Diameter of the disk is 1m and time taken to come to stop the disk by brake is Q.6sec.Square of radius of gyration is 0.Q. Calculate the torque capacity of the brake.
A. 8Q.4N-m
B. 458Q.6N-m
C. 6Q.4N-m
D. Noe of the listed
.
Answer: B
Explanation: M=E/θ.
Q. An automobile brake is only used to reduce the speed or bring the vehicle to hault.
A. Yes
B. No, it also be used to hold the car
C. Brake acts only onmoving vehicles
D. None of the mentioned
.
Answer: B
Explanation: It can also be used to hold the car stationary.
Q. Block brakes are never used in railway trains.
A. True
B. False
.
Answer: B
Explanation: Blocks brakes are commonly employed in railway trains.
Q. If torque capacity of a block brake is 240N-m and radius of drum is 2Q.mm with coefficient of friction 0.Q.
A. None of the listed
B. 285Q.14N
C. 344Q.42N
D. 233Q.62N
.
Answer: B
Explanation: N=M/μR.
Q. If initially drum of radius 200mm is rotating at Q.0rpm, then calculate the heat generated if frictional force acting is 1140N.
A. 3345W
B. 4456W
C. 5969W
D. 11938W
.
Answer: C
Explanation: Heat=Frictional forcexaverage velocity.
Q. In a block brake with short shoe, it is assumed that friction force and normal reaction are concentrated at the midpoint of the shoe.
A. True
B. False
.
Answer: A
Explanation: The angle of contact is less than 45⁰ and hence the assumption is valid.
Q. The pressure intensity at an element on long shoe brake varies directly with the sin of the pressure angle of the element of friction lining.
A. True
B. False
.
Answer: B
Explanation: p=Cxcos(Ǿ).
Q. The equivalent coefficient of friction in case of block brake with long shoe is denoted by μ[4Sinθ/2θ+sin4θ].
A. True
B. False
.
Answer: B
Explanation: μ[4Sinθ/2θ+sin2θ].
Q. In pivoted block brakes, moment of frictional force about pivot is non zero.
A. True
B. False
.
Answer: B
Explanation: Pivot point is selected such that moment of frictional force about pivot point is zero.
Q. Shoe is constrained to move towards the drum to compensate for the moment acting.
A. Yes
B. It compensates for wear
C. It compensates for both wear and moment
D. None of the listed
.
Answer: B
Explanation: It compensates for the wear which is constant for all points.
Q. A pivoted double block brake has a drum radius of 280mm with two shoes subtending an angle of Q.0⁰. Calculate the distance of pivot from axis of drum.
A. 32Q.5mm
B. 3Q.3mm
C. 28Q.5mm
D. None of the mentioned
.
Answer: B
Explanation: h=4Rsinθ/2θ+sin2θwhere θ=Q.0/Q.
Q. A pivoted double block brake has a drum radius of 280mm with two shoes subtending an angle of Q.0⁰. Maximum pressure intensity is 0.5N/mm². If the width of friction lining is 90mm, find the torque capacity f each shoe. Assume coefficient of friction as 0.Q.
A. 789N-m
B. Q.81N-m
C. 945N-m
D. None of the listed
.
Answer: B
Explanation: M=2μR²wpsinθ.
Q. A pivoted double block brake has a drum radius of 280mm with two shoes subtending an angle of Q.0⁰. Maximum pressure intensity is 0.5N/mm². If the width of friction lining is 90mm, find the reaction at pivot in horizontal direction. Assume coefficient of friction as 0.Q.
A. None of the listed
B. 21123N
C. 17200N
D. 16789N
.
Answer: C
Explanation: R(x)=Rwp(2θ+sin2θ)/Q.
Q. A pivoted double block brake has a drum radius of 280mm with two shoes subtending an angle of Q.0⁰. Maximum pressure intensity is 0.5N/mm². If the width of friction lining is 90mm, find the reaction at pivot in horizontal direction. Assume coefficient of friction as 0.Q.
A. None of the listed
B. 2113N
C. 1720N
D. 3440N
.
Answer: D
Explanation: R(y)=μRwp(2θ+sin2θ)/Q.
Q. The intensity of normal pressure between the friction lining and the brake drum at any point is proportional to square of the vertical distance from the pivot.
A. It is independent
B. Proportional to vertical distance linearly
C. Inversely proportion to vertical distance
D. None of the listed
.
Answer: B
Explanation: It is proportional to the vertical distance linearly.
Q. The coefficient of friction in internally expanding brakes is constant.
A. True
B. No, it varies with increase in speed linearly
C. It decreases with increase in speed linearly
D. None of the listed
.
Answer: A
Explanation: Coefficient of friction is constant in these types of brakes.
Q. The centrifugal force acting on the shoe can never be omitted.
A. True
B. Always omitted
C. Depends on the magnitude
D. There is no centrifugal force acting
.
Answer: B
Explanation: Centrifugal force on the internal expanding brakes is generally neglected as it is very small.
Q. These kinds of brakes require little maintenance.
A. Yes
B. No
C. Very much maintenance is required
D. Depends on the working environment
.
Answer: A
Explanation: Very little maintenance is required as there is less wear.
Q. In internally expanding brake, a large actuating force produces a small braking torque and hence this brake isn’t used generally.
A. True
B. No, small actuating braking torque is produces
C. Zero actuating force is required
D. None of the listed
.
Answer: B
Explanation: Small actuating force produce large braking torque.
Q. Heat dissipating capacity of internally expanding brakes is a problem.
A. True
B. No
C. There is no heat generated
D. Heat is convected away on its own
.
Answer: A
Explanation: It has relatively poor dissipation of heat.
Q. Internally expanding brakes never suffer the problem of self-locking.
A. True
B. Wear might lead to self-locking
C. Brakes are never self-locked
D. None of the listed
.
Answer: B
Explanation: Due to improper design, wear may be caused which might lead to self-locking of brakes.
Q. Moment of normal force and frictional forces about the pivot axis are 640000N-mm and 250000N-mm respectively. If force acts at a distance of 190mm from the pivoted point, calculate the actuating force.
A. Q.7Q.6N
B. 205Q.6N
C. 322Q.5N
D. 445Q.5N
.
Answer: B
Explanation: P=M(n)-M(f)/C.
Q. Preloading is recommended for bearings.
A. True
B. False
.
Answer: A
Explanation: Preloading removes the internal clearances.
Q. Needles bearings have not much load capacity as they are quite small.
A. True
B. False
.
Answer: B
Explanation: Needle bearings have quite large loading capacity as compared to their size.
Q. In both simple band brake and differential band brake, at least one end of the band passes through fulcrum.
A. Both the ends
B. Neither end
C. One end
D. None of the listed
.
Answer: B
Explanation: In differential, neither end of the brake passes through fulcrum.
Q. Is it possible to prevent back rotation of drum?
A. Yes by using back stop brake
B. No
C. Depends on the angular velocity
D. Only in some specific cases
.
Answer: A
Explanation: Back stop brake can be used to prevent rotation of drum.
Q. A self-locking differential brake and back stop brakes is same thing.
A. True
B. False
.
Answer: A
Explanation: Back stop brake is other name of self locking differential brake.
Q. Band brake has complex construction with large number of parts.
A. Yes
B. It has simple construction
C. It has simple constructions but large number of parts
D. It has complicated construction but small number of parts
.
Answer: B
Explanation: Band brake has simple construction with small number of parts.
Q. Band brakes require _____ maintenance.
A. Little
B. Zero
C. Much
D. None of the listed
.
Answer: A
Explanation: There is relatively less maintenance required as there are small number of parts and hence chances of brake going out of order is less.
Q. The wear of band brake is even.
A. True
B. False
.
Answer: B
Explanation: There is uneven wear from one side to other side of the friction lining.
Q. Calculate the braking torque if tension in the two sides is 3500N and 1980N with radius of drum being 160mm.
A. None of the mentioned
B. 24Q.20N-m
C. 22Q.4N-m
D. 27Q.6N-m
.
Answer: B
Explanation: Braking torque=(3500-1980)x160/Q.00.
Q. Disk brakes have low torque transmitting capacity in high volumes.
A. True
B. False
.
Answer: B
Explanation: They have high torque transmitting capacity in low volumes.
Q. In drum brakes, as the temperature increases coefficient of friction ______
A. increases
B. decreases
C. remains same
D. Can’t be determined
.
Answer: D
Explanation: Coeffecient of friction varies inversely with the temperature.
Q. Loss of torque transmitting capacity at high temperatures is called
A. Fading
B. Rolling
C. Drifting
D. Planking
.
Answer: A
Explanation: Terminology.
Q. Disk brakes largely suffer from the problem of self-locking.
A. Yes
B. No
C. Self-locking but it depends on radius of the wheel rotating
D. Material dependent
.
Answer: B
Explanation: There is no problem of self-locking in disk brakes.
Q. Disk brakes can be used for opposite rotation of disk also.
A. No they are effective for one direction of motion only
B. They can be used
C. Poor efficiency in opposite direction
D. None of the listed
.
Answer: A
Explanation: Disk brakes are equally effective for both direction of motion.
Q. The disk brake torque is linearly proportional to the actuating force.
A. Yes
B. No, it is proportional to its square
C. Proportional to its cube
D. Independent of force
.
Answer: A
Explanation: M=μPr.
Q. Belt, chain and rope are called rigid drives.
A. True
B. Belt is a flexible drive only
C. All three are flexible drives
D. None of the listed
.
Answer: B
Explanation: They all are flexible drive examples.
Q. In flexible drives, rotary motion of driving shaft is directly converted to rotary motion of driven shafts
A. Yes
B. No, translator motion is involved
C. No, Cylindrical motion is involved
D. No, Parabolic motion is involved
.
Answer: B
Explanation: It is first converted into translator and then into rotary.
Q. Flexible drive can absorb shock loads and damp vibrations.
A. True
B. No
C. Depends on the load applied
D. Doesn’t damp vibrations
.
Answer: A
Explanation: Intermediate link is long and flexible.
Q. Velocity ratio in both flexible and rigid drive is constant.
A. True
B. False
.
Answer: B
Explanation: In flexible drive, velocity ratio is not constant.
Q. Is there any worry for overloading conditions in flexible belt drives?
A. Yes
B. No
C. Only after a particular threshold limit
D. Depends on external factrors
.
Answer: B
Explanation: In case of overloading, belt slips over the pulley and hence protect it from the overload.
Q. V belts have v shaped cross section.
A. No, rectangular
B. No, trapezium
C. No, circular
D. No, spherical
.
Answer: B
Explanation: They have trapezoidal cross section.
Q. The force of friction between belt and V grooved pulley is high.
A. Yes, supported by wedge action
B. No
C. There is no wedge action involved
D. None of the listed
.
Answer: A
Explanation: Due to wedge action, force of friction is high.
Q. V belts result in smooth and quite operation even at high speeds.
A. Yes
B. No they are very noisy
C. They are not endless and hence not smooth motion
D. None of the listed
.
Answer: A
Explanation: V belts are endless.
Q. The efficiency of flat belt drive is 35%. If all the parameters are same and flat belt is replaced by V belt, than the efficiency of V belt will be?
A. <35% B. >35%
C. =35%
D. Cant be determined
.
Answer: A
Explanation: The efficiency of flat belt drive is more that V belt drive.
Q. There is problem of bending stress in the V belt drive.
A. True
B. False
.
Answer: A
Explanation: The ratio of cross sectional height to pulley diameter is high.
Q. The layer of a belt is generally called as
A. Ply
B. Layer
C. Segment
D. Sediment
.
Answer: A
Explanation: Terminology.
Q. Velocity ratio for chain drive is lesser than that for belts.
A. Yes
B. No
C. In some cases
D. Can’t be determined
.
Answer: B
Explanation: Velocity ratio for chain drives is about 15:1 while for belts it is around 7:Q.
Q. Fabric rubber belts are not widely used as they can’t be operated at high speeds.
A. They can’t be used at velocities 50m/s
B. They can be used at high velocities
C. Limiting velocity is 20m/s
D. None of the listed
.
Answer: B
Explanation: These belts can be operated at 300m/s.
Q. Power transmitting capacity of V belts is more than that of flat belt.
A. Yes
B. No
C. Only for V angle > 15
D. None of the listed
.
Answer: A
Explanation: Coefficient of friction is Q.92times of flat belts in V belts for identical materials.
Q. The optimum velocity of the belt for maximum transmission is given by √P/6m.
A. Yes
B. No, by replacing 6 by 3
C. Replacing 6 by 9
D. None of the listed
.
Answer: B
Explanation: It is given by √P/3m.
Q. Creep is the slight absolute motion of the belt as it passes over the pulley.
A. Yes
B. No, it is a relative motion
C. None of the listed
D. It is absolute motion
.
Answer: B
Explanation: It is a relative and not absolute motion.
Q. In horizontal belt, the loose side is generally kept on the bottom.
A. True
B. False
.
Answer: B
Explanation: Loose side is kept on the top so that arc of contact increases and hence efficiency of the drive increases.
Q. Vertical drives are preferred over horizontal.
A. True
B. False
.
Answer: B
Explanation: In vertical drive, gravitational force on the belt causes slip which reduces the efficiency.
Q. The law of belting states that the centreline of the belt when it approaches a pulley must not lie in the midplane of the pulley.
A. True
B. False
.
Answer: A
Explanation: The centreline must lie in the midplane.
Q. It is possible to use the belting reverse direction without violating the law of belting.
A. True
B. False
.
Answer: B
Explanation: Law of belting is violated if belt is used in reverse direction.
Q. A shorter centre distance is always preferred in belt drives.
A. Yes due to stability
B. No due to stability
C. Yes due to instability
D. No due to instability
.
Answer: A
Explanation: It is more stable and compact.
Q. If velocity ratio is less than 3, then centre distance is given by D+.5d.
A. True
B. False
.
Answer: B
Explanation: It is given by D+Q.5d.
Q. If velocity ratio is more than 3, then centre distance is given by 2D.
A. By 3D
B. By D
C. By 4D
D. By 5D
.
Answer: B
Explanation: It is given by D.
Q. Is it possible to reduce the centre distance as much as we want?
A. Yes power transmission increases
B. No
C. Can’t be cited
D. None of the listed
.
Answer: B
Explanation: It depends on physical dimension and the minimum angle of wrap required to transfer the required power.
Q. The diameter of the shorter pulley in leather belt drive is 265mm. It is rotating at 1440 rpm. Calculate the velocity of the belt.
A. 25m/s
B. 20m/s
C. 30m/s
D. None of the mentioned
.
Answer: B
Explanation: v=πdn/60×Q.00.
Q. Calculate the angle of wrap if diameter of the two pulleys are 550mm and 300mm. Also the centre distance is 2800mm.
A. 17Q.8⁰
B. 16Q.8⁰
C. 15Q.3⁰
D. None of the mentioned
.
Answer: A
Explanation: ὰ=180 – 2sin¯¹(D-d/2C..
Q. Calculate the arc of contact if diameter of the two pulleys are 550mm and 300mm. Also the centre distance is 2800mm.
A. Q.04
B. Q.03
C. Q.01
D. Q.02
.
Answer: D
Explanation: ὰ=180 – 2sin¯¹(D-d/2C.. Factor=1+ (Q.04-1)(180-17Q.8)/(180-170).
Q. Calculate the belt length if diameter of the two pulleys are 550mm and 300mm. Also the centre distance is 2800mm.
A. Q.5m
B. Q.66m
C. Q.94m
D. Q.26m
.
Answer: C
Explanation: L=2C + π(D+D./2 + (D-D.²/4C.
Q. Crowns are never mounted on the pulley.
A. True
B. False
.
Answer: B
Explanation: Crowns are used to avoid slip in case of misalignment or non-parallelism.
Q. In a cast iron pulley minor axis is generally kept in the plane of rotation.
A. True
B. False
.
Answer: B
Explanation: Keeping minor axis in plane of rotation increases the cross section.
Q. The number of V belts required for a given application are given by (ignoring correction factor for arc of contact and belt length) Transmitted power/kW rating of single belt x Industrial Service Factor.
A. True
B. False
.
Answer: B
Explanation: It is given by Transmitted power x Industrial Service Factor /kW rating of single belt.
Q. The pitch diameter of bigger pulley D in terms of small diameter d is given by
A. dx[speed of smaller pulley/speed of bigger pulley].
B. dx[speed of bigger pulley/speed of smaller pulley].
C. d
D. None of the mentioned
.
Answer: A
Explanation: Product of diameter and speed of pulley is constant.
Q. If maximum tension in the belt is 900N and allowable belt load is 500N. Calculate the number of belts required to transmit power.
A. 2
B. 3
C. 4
D. 5
.
Answer: A
Explanation: No of belts=900/500.
Q. The belt tension is maximum when velocity of belt is 0.
A. It is max at v=infinity
B. True
C. It is velocity independent
D. It has a constant value
.
Answer: A
Explanation: P₁-mv²/P₂-mv²=e^(fa/sinθ/2). Hence belt tension is maximum when v=0.
Q. If belt tension in the two sides is 730N and 140N and belt is moving with a velocity of Q.m/s, calculate the power transmitted.
A. Q.5kW
B. Q.9kW
C. Q.2kW
D. None of the mentioned
.
Answer: B
Explanation: Power=(P₁-P₂)xv.
Q. If tensions in the belt are P₁ and P₂, then find P₁-mv²/P₂-mv². Contact angle for smaller pulley is 156⁰, Groove angle is 36⁰ and coefficient of friction is 0.Q.
A. Q.21
B. Q.83
C. Q.66
D. Q.36
.
Answer: B
Explanation: P₁-mv²/P₂-mv²=e^(fὰ/sinθ/2).
Q. Is it possible to remove the slack from the belt?
A. Yes
B. No
C. It can be done but at the cost of strength
D. None of the listed
.
Answer: A
Explanation: A short length of belt is cut to remove slack provided it is not an endless belt.
Q. A ribbed V belt is a negative drive.
A. Yes
B. No, it’s a positive drive
C. Zero drive
D. None of the listed
.
Answer: B
Explanation: It is a positive drive.
Q. The cross section of V belt consist of rubber backing to help engagement of teeth with sprocket.
A. Yes
B. No, it is used for protection
C. There is no rubber packing
D. None of the listed
.
Answer: B
Explanation: It is used for protecting the load carrying tension members.
Q. Ribbed V belt is not generally recommended as the output speed keeps fluctuating.
A. True
B. No, it is generally recommended
C. No variation in output speeds
D. None of the listed
.
Answer: B
Explanation: There is no variation in output speed in case of ribbed V belts.
Q. The ribbed V belts don’t require any type of lubrication like V belts.
A. True
B. Intense lubrication is required
C. No belts require any lubrication
D. Ribbed V belts can be operated with or without lubrication
.
Answer: A
Explanation: Ribbed V belts are free from lubrication problem.
Q. Ribbed V belts are very stable and can tolerate some misalignment without any malfunctioning.
A. True
B. False
.
Answer: B
Explanation: Ribbed V belts are very sensitive.
Q. Toothed belt is preferred over ribbed V belt.
A. Yes
B. No
C. They both imply to same thing
D. None of the listed
.
Answer: C
Explanation: Toothed belt and ribbed V belt is same thing.
Q. The idler pulley increases the power transmitting capacity of the belt drive.
A. True
B. False
.
Answer: A
Explanation: Idler pulley increases the arc of contact which further increases the power transmitting capacity.
Q. Adjusting screw can be used for adjusting belt tension?
A. Yes
B. No
C. Distance can never be changed
D. None of the listed
.
Answer: A
Explanation: Adjusting screw varies the distance between electric motor and bedplate.
Q. A chain drive consist of an endless chain wrapped around two sprockets.
A. True
B. False
.
Answer: A
Explanation: This is the basic definition of chain drive.
Q. The chain drive is same as gear drive.
A. Yes
B. No, it is intermediate between belt and gear drive
C. It is superior to gear drive
D. It is inferior to gear drive
.
Answer: B
Explanation: Chain drive is intermediate between belt drive and gear drive.
Q. Gear drives are preferred over chain drives for long centre distances.
A. Yes
B. No, they require additional idle gears.
C. No idler gears are required
D. None of the listed
.
Answer: B
Explanation: Gear drive will require additional idler gears.
Q. Belt drives have compact construction as compared to chain drives.
A. Yes
B. No, chain drives have compact construction
C. Both have same construction
D. Can’t be cited
.
Answer: B
Explanation: Chain drives have overall small dimensions and hence resulting in compact constructions.
Q. The maximum achievable efficiency of the chain drives is about 80%.
A. It is about 50%
B. It is about 96-98%
C. It is about 75%
D. It is always <40%
.
Answer: B
Explanation: Maximum achievable efficiency is around 96-98%.
Q. Chain drives suffer from wear problems.
A. Yes, chain might leave the sprocket
B. No, there is no wear problem
C. Wear is insignificant in chain drives
D. None of the listed
.
Answer: A
Explanation: Wear increases pitch of the chain which leads to chain leaving the sprocket.
Q. For non-parallel shafts, chain drives are highly recommended.
A. True
B. Gear drive is preferred
C. Depends on the transmission ratio
D. Can’t be stated
.
Answer: B
Explanation: Bevel or worm gears can be used in this case. Chain drives isn’t suitable for this application.
Q. The velocity of the chain is always constant in case of chain drive.
A. Yes
B. No, it can never be constant
C. It is constant above a particular value
D. Can’t be stated
.
Answer: B
Explanation: Velocity isn’t constant in chain drive which results in non-uniform speed of the driven shaft.
Q. Chain drives require little or no maintenance and creates no noise.
A. True
B. False
.
Answer: B
Explanation: Chain drives require lubrication at proper periods and also generates noise.
Q. In roller chains, there is sliding friction between roller and sprocket teeth.
A. True
B. False
.
Answer: B
Explanation: Rollers are freely fitted on the bushes and during engagement turn with teeth. This results in rolling friction.
Q. In the designation ‘04B’, pitch of the chain is?
A. Q.7mm
B. Q.35mm
C. 4mm
D. None of the mentioned
.
Answer: B
Explanation: Pitch=[04/16]x2Q.4mm.
Q. The designation ‘04B’ is as per ANSI series.
A. Yes
B. No, it is as par British standards
C. One digit is missing
D. None of the listed
.
Answer: B
Explanation: The letter B indicates British Standard Series.
Q. Wear ultimately results in ride in of the chain on sprocket teeth.
A. True
B. Ride out
C. Ride up
D. Ride down
.
Answer: B
Explanation: Wear causes ride out of chain.
Q. Galling is a stick slip phenomenon.
A. True
B. No, it is only a stick phenomenon
C. No, it is only a slip phenomenon
D. Can’t be stated
.
Answer: A
Explanation: During high tension, welds are formed at the high spot of contacting area which are subsequently broken due to relative motion.
Q. A gear meshes with another gear and a sprocket meshes with another sprocket.
A. True
B. False
.
Answer: B
Explanation: A sprocket meshes with with an intermediate link which further meshes with another sprocket.
Q. The number of links of the chain should be always ______
A. Odd
B. Even
C. Multiple of 3
D. None of the listed
.
Answer: B
Explanation: The odd number of teeth are meshed with even number of links.
Q. In chain drives, vertical drives are generally avoided.
A. True
B. False
.
Answer: B
Explanation: Sag causes the chain to leave the profile of the teeth at lower side.
Q. Sum of number of links and number of teeth of the sprocket is _____
A. Odd
B. Even
C. Odd or Even
D. None of the listed
.
Answer: A
Explanation: Number of links are even while number of teeth on the sprocket are odd.
Q. The driving sprocket has 19 teeth and rotates at 1Q.0rpm. The pitch of the chain is 18mm. Calculate the velocity of the chain.
A. Q.6m/s
B. Q.3m/s
C. Q.8m/s
D. Q.1m/s
.
Answer: B
Explanation: v=zpn/60×Q.00.
Q. Calculate the pitch circle diameter of the driving pulley is pitch is given as 18mm and sprocket has 19 teeth.
A. 1Q.33mm
B. Q.Q.36mm
C. Q.Q.66mm
D. Q.Q.33mm
.
Answer: B
Explanation: D=p/sin(180/z).
Q. Driving and driven pulleys are rotating at Q.00rpm and 500rpm. If number of teeth on driving sprocket are 20, find number of teeth in the driven sprocket.
A. 41
B. 40
C. Q.
D. 11
.
Answer: B
Explanation: n₁z₁=n₂z₂.
Q. If centre distance for a chain drive is 750mm with number of teeth on the driving and driven sprockets being 40 and 20 respectively, then calculate the number of links required. Given: Pitch is taken as 19mm.
A. 112
B. 1Q.
C. 111
D. Q.9
.
Answer: B
Explanation: 2(a/p) + (z₁+z₂)/2 +( z₂- z₁/2π)²xp/a.
Q. In silent chain sprocket teeth have a rectangular profile.
A. Yes rectangular
B. No trapezoidal
C. No circular
D. No hyperbolic
.
Answer: B
Explanation: They have a trapezoidal profile.
Q. Roller chains have less reliability as compared to roller chains.
A. True
B. False
.
Answer: B
Explanation: Silent chains have laminated structure and hence are more reliable.
