# Physics – Multiple Choice Questions (MCQ) with Answers

**Physics – Multiple Choice Questions (MCQ) with Answers **

**1-A decrease in the Helmholtz function of a system is equal to:**

(A) change in temperature

(B) external work done

(C) change in internal energy

(D) all the above

**2-In a gas the transport of momentum gives rise to the phenomenon of:**

(A) viscosity

(B) conduction

(C) diffusion

(D) volume

**3-Joule-Thomson effect is related to:**

(A) adiabatic compression

(B) adiabatic expansion

(C) isothermal expansion

(D) isothermal compression

**4-The specific heat of a solid is 5 cal/g/ºC. Then heat required to raise its temperature by 20 ºC is:**

(A) 150 cal

(B) 25 cal

(C) 100 cal

(D) 15 cal

**5-P, T are ****ρ** **are the pressure, absolute temperature and density of an ideal gas, then:**

(A) *PT/*ρ = constant

(B) *P*ρ/*T* = constant

(C) *PT* ρ= constant

(D)* P/*ρ*T *= constant

**6-For the system of diatomic gas the number of degrees of freedom are:**

(A) 2

(B) 4

(C) 5

(D) 6

**7-An LCR series ac circuit has the values of the resistance 400 ****Ω****, capacitive reactance 400 ****Ω** **and inductive reactance 100 ****Ω** **then the total impedance of the circuit:**

(A) 200 Ω

(B) 400 Ω

(C) 500 Ω

(D) 800 Ω

**8-In an electromagnetic wave, the cross product of electric field E and magnetic field B gives:**

(A) amplitude

(B) frequency

(C) velocity

(D) direction of travel

**9-If dQ is the amount of heat supplied and dW is the work done, then in isothermal process:**

(A) *dQ *+ *dW *= *0 *

(B) *dQ *– *dW *= *0*

(C) *dW */ *dQ = 0*

(D) None of the above

**10-The physical quantity analogous to mass in circular motion is:**

(A) moment of inertia

(B) force

(C) weight

(D) angular velocity

**11-The value of g is 980 cm/s ^{2}. If the unit of length is taken as 1 km and unit of time as 1 minute, then the value of g becomes:**

(A) 35.3 km/min^{2}

(B) 36.2 km/min^{2}

(C) 30.3 km/min^{2}

(D) 980 km/min^{2}

**12-The escape velocity for a body on the earth is 11.2 km/s. If the radius of the earth is increased 4 times, then the escape velocity would be:**

(A) 44.8 km/s

(B) 33.8 km/s

(C) 25.7 km/s

(D) 22.4 km/s

**13-Compton effect is experimentally observed for:**

(A) visible

(B) ultraviolet

(C) X-rays

(D) γ-rays

**14-The e.m.f of a cell is quoted as 1.5V. This means that the cell can supply:**

(A) 1.5A of current

(B) 1.5 coulombs of charge

(C) 1.5 Ωresistance

(D) 1.5 joules of energy per coulomb of charge

**15-A ray of light is shone onto a prism. The light cannot be:**

(A) deviated

(B) dispersed

(C) focused

(D) reflected

**16-Cathode rays are:**

(A) Beam of atoms moving towards cathode

(B) Beam of electrons emitted by cathode

(C) Is a beam of negatively charged ions moving towards anode

(D) Are electromagnetic waves

**Answers:**

1-B , 2-A , 3-B , 4-C , 5-D , 6-D , 7-C , 8-D , 9-A , 10-A , 11-A , 12-A , 13-C , 14-D, 15-D , 16-C