## Units and Measurement Questions and Answers Part-11

1. One femtometer is equivalent to
a) $10^{15} m$
b) $10^{-15} m$
c) $10^{-12} m$
d) $10^{12} m$

Explanation: One femtometer is equivalent to $10^{-15} m$

2. How many wavelength of $Kr^{86}$ are there in one metre
a) 1553164.13
b) 1650763.73
c) 652189.63
d) 2348123.73

Explanation: According to the definition

3. Which of the following pairs is wrong
a) Pressure-Baromter
b) Relative density-Pyrometer
c) Temperature-Thermometer
d) Earthquake-Seismograph

Explanation: Pyrometer is used for measurement of temperature.

4. Select the pair whose dimensions are same
a) Pressure and stress
b) Stress and strain
c) Pressure and force
d) Power and force

Explanation:

5. Dimensional formula $ML^{-1}T^{-2}$  does not represent the physical quantity
a) Young's modulus of elasticity
b) Stress
c) Strain
d) Pressure

Explanation:

6. Dimensional formula $ML^{2}T^{-3}$  represents
a) Force
b) Power
c) Energy
d) Work

Explanation:

7. The dimensions of calorie are
a) $ML^{2}T^{-2}$
b) $MLT^{-2}$
c) $ML^{2}T^{-1}$
d) $ML^{2}T^{-3}$

Explanation: Calorie is the unit of heat i.e., energy. So dimensions of energy = ML2T-2

8. Whose dimensions is $ML^{2}T^{-1}$
a) Torque
b) Angular momentum
c) Power
d) Work

Explanation: Angular momentum = mvr = MLT-1 * L = ML2T-1

9. If C and R represent capacitance and resistance respectively, then the dimensions of RC are
a) $M^{0}L^{0}T^{2}$
b) $M^{0}L^{0}T$
c) $ML^{-1}$
d) None of the above