Physical World And Measurement MCQs
1.How many numbers of base SI units are there?
(a) 5
(b) 10
(c) 7
(d) 9
Answer: (c) 7
2. What is the percentage error in the measurement of the kinetic energy of a body, if there is a positive error of 50% in the speed of the body
(a) 125%
(b) 30%
(c) 50%
(d) 100%
Answer: (d) 100 %
3. What is the dimensional formula of torque and energy
(a) [ML-3T-2] and [MLT-2]
(b) [ML2T-2] and [MLT-2]
(c) [ML2T-2] and [ML2T2]
(d) [MLT2] and [ML2T2]
Answer: (c) [ML2T-2] and [ML2T2]
4. Identify the physical parameters that are having the same dimensions from the below-given list:
(i) Magnetic field
(ii) Energy density
(iii) Refractive index
(iv) Young’s modulus
(v) Dielectric constant
(a) (ii) and (iv)
(b) (i) and (v)
(c) (iii) and (iv)
(d) (iv) and (iii)
Answer: (a) (ii) and (iv)
5. Which the following is a dimensionless quantity
(a) Refractive index
(b) Gravitational constant
(c) Velocity
(d) Planck’s constant
Answer: (a) Refractive index
6. Calculate the value of the dot product of the two vectors whose magnitudes are 3 units and 4 units and their resultant is 1 unit.
(a) +6 units
(b) 0
(c) -12 units
(d) -1 unit
Answer: (c) -12 units
7. Following are the readings obtained while measuring the diameter of a wire by using the screw gauge0 mm is the main scale reading
52 divisions are the circular scale reading
8. What is the diameter of the wire if 1 mm on the main scale is equal to the 100 divisions on the circular scale
(a) 0.016 cm
(b) 0.052 cm
(c) 0.15 cm
(d) 0.05 cm
Answer: (b) 0.052 cm