Units and Measurement Questions and Answers Part-18

1. The dimension of quantity \[\left(L\diagup RCV\right)\] is
a) \[\left[A\right]\]
b) \[\left[A^{2}\right]\]
c) \[\left[A^{-1}\right]\]
d) None of these

Answer: c
Explanation:
q171

2. The dimension of the ratio of angular to linear momentum is
a) \[M^{0}L^{1}T^{0}\]
b) \[M^{1}L^{1}T^{-1}\]
c) \[M^{1}L^{2}T^{-1}\]
d) \[M^{-1}L^{-1}T^{-1}\]

Answer: a
Explanation:
q172

3. The pair having the same dimensions is
a) Angular momentum, work
b) Work, torque
c) Potential energy, linear momentum
d) Kinetic energy, velocity

Answer: b
Explanation: Dimension of work and torque = [ML2T-2]

4. The dimensions of surface tension are
a) \[ML^{-1}T^{-2}\]
b) \[MLT^{-2}\]
c) \[ML^{-1}T^{-1}\]
d) \[MT^{-2}\]

Answer: d
Explanation:
q174

5. In the following list, the only pair which have different dimensions, is
a) Linear momentum and moment of a force
b) Planck's constant and angular momentum
c) Pressure and modulus of elasticity
d) Torque and potential energy

Answer: a
Explanation: Linear momentum = Mass * Velocity =[MLT-1]
Moment of a force = Force * Distance = [ML2T-2]

6. If R and L represent respectively resistance and self inductance, which of the following combinations has the dimensions of frequency:
a) \[\frac{R}{L}\]
b)\[\frac{L}{R}\]
c) \[\sqrt{\frac{R}{L}}\]
d) \[\sqrt{\frac{L}{R}}\]

Answer: a
Explanation:
q176

7. If velocity v , acceleration A and force F are chosen as fundamental quantities, then the dimensional formula of angular momentum in terms of v, A and F would be
a) \[FA^{-1}v\]
b) \[Fv^{3}A^{-2}\]
c) \[Fv^{2}A^{-1}\]
d) \[F^{2}v^{2}A^{-1}\]

Answer: b
Explanation:
q177

8. The dimensions of permittivity \[\epsilon_{0}\] are
a) \[A^{2}T^{2}M^{-1}L^{-3}\]
b) \[A^{2}T^{4}M^{-1}L^{-3}\]
c) \[A^{-2}T^{-4}ML^{3}\]
d) \[A^{2}T^{-4}M^{-1}L^{-3}\]

Answer: b
Explanation:
q178

9. Dimensions of the following three quantities are the same
a) Work, energy, force
b) Velocity, momentum, impulse
c) Potential energy, kinetic energy, momentum
d) Pressure, stress, coefficient of elasticity

Answer: d
Explanation: [Pressure] = [Stress] = [coefficient of elasticity] = [ML-1T-2]

10. The dimensions of Planck's constant and angular momentum are respectively
a) \[ML^{2}T^{-1}\]  and \[MLT^{-1} \]
b) \[ML^{2}T^{-1}\]  and \[ML^{2}T^{-1} \]
c) \[MLT^{-1}\]  and \[ML^{2}T^{-1} \]
d) \[MLT^{-1}\]  and \[ML^{2}T^{-2} \]

Answer: b
Explanation: \[ML^{2}T^{-1}\]  and \[ML^{2}T^{-1} \]