# Physics past papers

### Physics past papers

corrections are appreciated.

Paper I.

1. The angular momentum of a particle under the influence of a central force is
a) Infinite b) Negative c) Zero d) CONSTANT

2. Transverse component of the central force acting on a particle to keep it moving along a path is
a) mv2r b)mv2/r c) ZERO d) constant

3. Law of Intertia can be defined in
a) Accelerated system b) NON ACCELERATED SYSTEM c) both a) & b) d)None of these

4. The K.E of the particle executing a uniform circular motion:
a) Increases b) decreases c) REMAINS SAME d)None of these

5. What type of force acts on a raindrop to reduce its speed?
a) Gravitational force b) FORCE OF FRICTION c) Electromagnetic force d) drag force

6. The branch of heat relating to the measurement of temperature of body is called
a) THERMOMETRY b) photometry c) ellipsometry d) calorimetry

7. Which type of ideal gas will have the largest value for Cp-Cv
a) Monoatomic b) diatomic c) polyatomic d) THE VALUE IS SAME FOR ALL

8. What would be the most likely value for Ct, the molar heat capacity at constant temperature
a) Zero b) zero<Ct< Cv c) Cv<Ct<Cp d) CT= INFINITE

9. For which of the following process the entropy changes zero?
a) Isobaric b) isothermal c) ADIABATIC d) isochoric

10. The zeroth law of thermodynamics helps to define the term
a) TEMPERATURE b) pressure c) volume d) density

11. The law of conservation of mass in fluid dynamics can be expressed as
a) Av= constant b) RHO AV= CONSTANT c) P+(1/2)rho V + rho gy = constant d)None of these

12. The SI Unit of Viscosity is
a) N-S/M2 b) Dynes-s/cm2 c) N-s/m dynes-s/cm

13. The equation of the continuity requires that the total mass within certain volume must remain constant:
a) If there are sources as well as sinks
B) IF THERE ARE NO SOURCES & SINKS
c) If there are sources only
d) If there are sinks only

14. If the length of the “L” and the total force acting on it is “F” then surface tension given is
a) F*L b)F.L C) F/L d) L/F

15. If the particle of liquid which pass through a certain point do not follow the same path, as that followed by the particles that passed the same point previously the liquid is said to have
a) Steady b) NON STEADY FLOW c) turbulent flow d)None of these

16. The potential energy of a simple harmonic oscillator is
a) –Kx b) –Kx2 c) 1/2 KX2 D) -1/2 KX2

17. Types of the mechanical weaves are
A) LONGITUDINAL AND SOUND WAVES
c) Longitudinal and transverse waves
d) Transverse & x-rays

18. The refracted ray bends towards the normal when it enters from
A) RARE TO DENSER MEDIUM
b) denser to rare medium
c) Air to vacuum
d) None of these

19. On a reflection from a fixed end, a transverse wave undergoes a phase change of___ degrees
a) 90 B) 180 c) 270 d) 360

20. Resolving power of a gratting can be written as:
a) LAMBA/DEL LAMDA b) del theta/del lamda c) del lamda/lamda d) del lamda/del theta

Paper II

1. Lorentz force is the sum of:
a) Gravitational and centripetal force
B) ELECTRIC AND MAGNETIC FORCE
c) Magnetic and nuclear force
d) Electrical and nuclear force

2. The areas under the hysteresis loop is proportional to
a) Magnetic energy density
b) Thermal energy per unit volume
C) ELECTRIC ENERGY PER UNIT VOLUME
d) Mechanical energy per unit volume

3. The frequency of A.C is measured using:
a) Multimeter b) avometer c) TACHOMETER d) speedometer

4. Del. E = rho/epsilon not is called
a) GAUSS’S LAW b) faraday’s law c) ampere’s law d) biot savart’s law

5. For computation of the rate at which the dipole radiates energy, the interaction of the normal component of __________ is done over sphere of radius R.

6. Semiconductor materials have _____ bonds.
a) Ionic b) COVALENT c) mutual d) metallic

7. The depletion region of a pn junction is formed:
a) During the manufacturing process
B) WHEN FORWARD BIAS IS APPLIED TO IT
c) Under reverse bias
d) When its temperature is reduced

8. The current amplification factor DC is given by:
A) IC/IE b) Ic/Ib c)Ib/Ie d) Ib/Ic

9. In amplitude modulation
a) Carrier frequency is changed
B) CARRIER AMPLITUDE IS CHANGED
c) Three sidebands are produced
d) Fidelity is improved

10. Demodulation
a) Is performed at the transmitting station
b) Removes side bands
c) Rectifies modulation signal
d) IS OPPOSITE OF MODULATION

11. Which of the following x-ray lines will have the largest frequency in a given element
a) K alpha b) K BETA c) L gamma d) it depends on the element

12. Which of these statements is a consequence of planck’s derivation of a radiation law?
a) Atomic oscillator can emit and absorb energy at discrete values only
b) ATOMIC OSCILLATOR CAN EMIT AND ABSORB ENERGY AT DISCRETE FREQUENCIES ONLY
c) Both A & B
d) None of these

13. The Zeeman effect without the spin of the electron is called_____ Zeeman effect
a) ANOMALOUS b) normal c) paschen d) None of these

14. Zero point energy of harmonic oscillator is
a) hw b) HW/2 c) zero d)hw2

15. According to pauli exclusion principle for two identical ferminions the total __ is antisymmetric
a) Matrix b) WAVE FUNCTION c) operator d) tensor

16. The decay rate of a radioactivity is measured in units of
a) CURIES b) roentgens c) rads d) rems

17. Why are the fission fragments usually radioactive?
a) They come originally from radioactive U235
b) They have a large neutron excess
c) THEY HAVE A LARGE BINDING ENERGY PER NUCLEON
d) They are moving at high speed

18. In a nuclear reactor, the function of the moderator is
a) To absorb neutrons
b) To keep the reactor from going critical
c) TO SLOW DOWN THE NEUTRONS
d) To absorb heat from the core

19. What is the main difficulty associated with the fusion process as a source of electrical power
a) The scarcity of fuel
b) THE COULOMB BARRIER
c) The radioactivity of the products
d) The danger of an explosion

20. Binding energy of a deuteron is
A) 2.22 MEV b) 2.8Mev c) 2.3Mev d)none of these