8. Write only the correct answers in the answer book. Do not reproduce the questions.

1) If the speed of particle is doubled then its kinetic energy becomes
(a) Doubled.
(b) Unchanged
(c) Four time.
(d) Half of the initial value

2) A ping - pong ball of mass m moving with velocity v bounces off a concrete surface with the same speed in the opposite direction. The change in it’s linear momentum is
(a) 2mw
(b) mv
(c) 1/2mv
(d) Zero

3) The work done by a force of 20 N in displacing an object through a distance of 5 cm is
(a) 100 J
(b) 4 J
(c) 400 J
(d) 1 J

4) The weight of an astronaut in space far from any planet in
(a) Zero
(b) Different than on earth
(c) Same on earth

5) A net force needed to give a mass of 250 kg an acceleration of 5 cm/sec2 is
(a) 25N
(b) 12.5N
(c) 10N
(d) 5N

6) A light year is a unit of
(a) Time
(b) Distance
(c) Velocity
(d) Intensity of light


8) A uniform spring with force constant K is cut into halves. Whet is the spring constant for one of the halves?
(a) Half of the original one.
(b) Twice the original one
(c) 1/4 of original one
(d) Same original one

9) A watt is the unit of
(a) Energy
(b) Power
(c) Work
(d) Capacity

10) Two bodies are in thermal equilibrium with each other if they have same
(a) Pressure
(b) Density
(c) Energy
(d) Temperature

11) The number of grams in one mole of Helium gas are
(a) 1gm/mole
(b) 4gm/mole
(c) 6 gm/mole
(d) 2 gm/mole


13) If a gas is compressed constant temperature, then the mean free path of the molecules of the gas,
(a) decreases
(b) remain the same
(c) increases

14) The melting point of the element Sulfur is 113 °C. It’s temperature at Fahrenheit scale is
(a) 45 °F
(b) 113 °F
(c) 63 °F
(d) 8l °F

15) Diffraction of waves occurs because of
(a) medium change
(b) uncertainty principle
(c) geometry of the object obstructing the wave
(d) none of these

16) Beats in sound are a result of
(a) two sound waves with different speeds
(b) in-homogenous medium
(c) superposition of two waves with different frequencies
(d) the relative motion of one of the sound source.


18) Longitudinal waves do not exhibit
(a) refraction
(b) reflection
(c) diffraction
(d) polarization

19) If mass of a simple pendulum is doubled, it’s period
(a) remain unchanged
(b) doubled
(c) becomes half of the original
(d) None of these

20) Diagnostic ultrasound of frequency 4.50 MHz is used to examine tumors in soft tissue. If the speed of sound in tissue is 1500 m/sec. The wave length of this wave in tissue is
(a) 6750 mm
(b) 4.50 mm
(c) 1500 mm
(d) 333.3 mm