NEET TEST SERIES 102 PHYSICS

1. A pendulum clock is 5 seconds fast at temperature of 15ºC and 10 seconds slow at a temperature of 30ºC. At what temperature does it give the correct time? (take time interval =24 hours)

a) 18 ºC

b) 20 ºC

c) 22 ºC

d) 25 ºC

2, 500 g of water and 100 g of ice at 0°C are in a calorimeter whose water equivalent is 40 g. 10 g of steam at 100°C is added to it. Then water in the calorimeter is : (Latent heat of ice = 80 cal/g, Latent heat of steam = 540 cal/ g)

3. The amount of charge Q passed in time t through a cross-section of a wire is Q = 5 t²+3 t+1. The value of current at time t = 5 s is

a) 9 A
b) 49 A
c) 53 A
d) None of these

4. The ionization energy of hydrogen atom is 6 eV. Following Bohr’s theory, the energy corresponding to a transition between 3rd and 4th orbit is

a) 3.40 eV
b) 1.15 eV
c) 0.85 eV
d) 0.66 eV

5. Nucleus of an atom whose atomic mass is 24 consists of

a) 11 electrons, 13 protons and 11 neutrons
b) 11 protons and 13 neutrons
c) 11 protons and 13 electrons
d) 11 protons, 11 electrons and 13 neutrons

6. When 3Li7 nuclei are bombarded by protons, and the resultant nuclei are 4Be8, the emitted particles will be

a) alpha particles
b) beta particles
c) gamma photons
d) neutrons

8. A gas is compressed from a volume of 2 m³ to a volume of at a constant pressure of 100 N/m². Then it is heated at constant volume by supplying 150 J of energy. As a result, the internal energy of the gas:

a) increases by 250 J

b) decreases by 250 J

c) increases by 50 J

d) decreases by 50 J

9. Gas at a pressure P₀ is contained in a vessel. If the masses of all the molecules are halved and their speeds are doubled, the resulting pressure P will be equal to

a) 4P₀
b) 2P₀
c) P₀
d) 0

10. A cell of internal resistance r is connected to an external resistance R. The current will be maximum in , if

a) R = r
b) R < r
c) R > r
d) R =r/2

11. In a p-n junction having depletion layer of thickness 10^-6 m the potential across it is 0.1 V. The electric field is

a) 10⁷  V/m
b) 10^-6  V/m
c) 10⁵  V/m
d) 10^-5  V/m

12. The gate for which output is high if at least one input is low?

a) NAND
b) NOR
c) AND
d) OR

13. Cooking gas containers are kept in a lorry moving with uniform speed. The temperature of the gas molecules inside will.

a) increase
b) decrease
c) remains the same
d) decrease for some and increase for others

14. Which of the following processes is adiabatic ?

a) Melting of ice
b) Bursting of tyre
c) Motion of piston of an engine with constant speed
d) None of these

15. The relaxation time in conductors

a) increases with the increases of temperature
b) decreases with the increases of temperature
c) it does not depends on temperature
d) all of sudden changes at 400 K

16. Two full turns of the circular scale of gauge cover a distance of 1 mm on scale. The total number of divisions on circular scale is 50. Further, it is found that screw gauge has a zero error of –0.03 mm. While measuring the diameter of a thin wire, a student notes the main scale reading of 3 mm and the number of circular scale division, in line with the main scale as 35. The diameter of the wire is

a) 3.32 mm
b) 3.38 mm
c) 3.73 mm
d) 3.30 mm

17. Assertion: Dimensional constants are those physical quantities which has constant value.
     Reason: Dimensional constants are dimensionless.

a) Both Assertion & Reason are True & the Reason is a correct explanation of the Assertion.
b) Both Assertion & Reason are True but Reason is not a correct explanation of the Assertion.
c) Assertion is True but the Reason is False.
d) Both Assertion & Reason are False.

18. Find the centre of mass of the given rod of length L as shown in fig.


a) 0.8 L
b) 0.75 L
c) L
d) 0.3 L