Test Series-12

## Instructions

• Your test contains 15 multiple choice questions with only one answer
• This is 30 min test.Please make sure you complete it in stipulated time
• You can Finish this test any time using 'Submit' button.
• Once finished you get a chance to review all question with correct answers and their solutions.

1.A parachutist after bailing out falls 50 m with out friction. When parachute opens ,it decelerates at 2m/s2. He reaches the ground with a speed of 3m/s. At what height ,did he bail out?
• 293m
• 213m
• 200m
• 111m

2. The timeperiod of a earth satellite in circular orbit is dependent of
• Mass of the satellite
• Both the mass and radius

3. A surface S enclosed a electric charge q. Let F be the electric flux passing through it.The flux will be maximum if the surface S is like
• Cube
• Spherical
• cylinderical
• Same in all the three

4..If suddenly the gravitational force of attraction between earth and a satellite revolving around it becomes zero,then the satellite will?
• Move towards earth
• Becomes stationary in the orbit
• continue to move in the orbit with same velocity
• Move tangentially to the orginal orbit with same velocity

5.M capcitors of same capicitance C are connected in parallel to the voltage source V.The total energy stored in the capacitor will be?
• CV
• CV2
• .5mCV2
• .5CV2/m

6. A Alpha nucleus of energy .5mv2 bombards a heavy nuclear target of charge Ze. Then the distance of closest approach for the alpha nucleus will be proportional to
• 1/Ze
• 1/m
• v2
• 1/v4

7. A projectile has been fired with speed 10m/s making an angle of 300 with the horizontal. Find the angle made by velocity vector of projectile with ground after 2sec of its firing? Take g=10m/s2
• 450
• 600
• Cant say anything
• None of the above

8. The ratio of the concentration of electrons to that of holes in a semiconductor is 7/5 and the ratio of currents is 7/4. Find the ratio of the drift velocities of electron and holes
• 5/4
• 4/5
• 3/4
• 4/7

9.What is the timetaken to heat one litre of water from 100 C to 400 C by a heater of 836 W
• 40s
• 80s
• 200s
• 150s

10.The acceleration of a particle is increasing with time ,then the v-t curve would be like
• concave Up
• concave down
• straight line
• None of these

11. A solid sphere of radius R,made up of a material of bulk modulus K is surrounded by a liquid in a cylinderical container. A massless piston of area A floats on the surface of the liquid.When a mass M is placed on the piston to compress the liquid,the fractional change in the radius of the sphere is
• Mg/2AK
• 3Mg/AK
• Mg/3AK
• Mg/AK

12. A thin ring is rotating abouts its own axis .If the density of the ring is 11300 Kg/m3,then the maximum permissible linear speed of the ring is
• 60m/s
• 40m/s
• 44.6m/s
• 42m/s
13. if the hollow bob of a simple pendulum be filled with mercury that drains out slowly,its time period
• increases continously
• decreases continously
• remains same
• first increases and then decreases
14. Gases begin to conduct electricity at low pressure becuase
• atoms break up into electrons and proton's
• at low pressure gases turn into plasma
• the electrons in atoms can move freely at low pressure
• colliding electrons can acquire higher kinetic energy due to increased mean free path leading to ionisation of atoms
14. An LCR series circuit is connected to a source of AC voltage.At resonance ,the phase difference between the applied voltage and current in the circuit is
• 180
• 45
• 90
• 0