Physics – Class 11 Mock Test 9

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Question 1 of 10

1. A liquid cools from 65°C to 55°C in 5 mins. If the surrounding temperature is 35℃, calculate the time taken for temperature to fall from 45°C to 35°C.

25min

30min

25sec

30sec

Question 1 of 10

Question 2 of 10

2. Two bodies in thermal equilibrium can have different pressures. True or False?

True

False

Question 2 of 10

Question 3 of 10

3. What is the number of molecules in 3 cubic metre of a gas at 3atm & 27°C?

4.58*10^-20

3.86*10^-20

2.17*10^-20

6.38*10^-20

Question 3 of 10

Question 4 of 10

4. Calculate the work done by the gas in an isothermal process from A to B. P_A = 1Pa, V_A = 3m³, P_B = 3Pa.

3.3J

-4.58J

-3.3J

Question 4 of 10

Question 5 of 10

5. Force on a particle is given by: F = -kxⁿ. For what values of n will the motion be oscillatory?

Any integer

It cannot be oscillatory for any value of n

Question 5 of 10

Question 6 of 10

6. For any gas the equation is state is PV=nRT. True or False?

False

True

Question 6 of 10

Question 7 of 10

7. Efficiency of a refrigerator can be greater than 1. True or False?

True

False

Question 7 of 10

Question 8 of 10

8. 20J of heat energy is extracted from a cold reservoir when 30J of work is done on a refrigerator. What is the coefficient of the refrigerator?

2/3

1/3

5/3

3/5

Question 8 of 10

Question 9 of 10

9. Two spheres, A & B, are made up of the same material. The radius of A is twice that of B, while the temperature of A is half that of B. What is their ratio of energy emitted per unit time (E_A : E_B)?

1/4

1/16

1/2

Question 9 of 10

Question 10 of 10

10. The number of molecules per unit volume in the sample is 20. The mass of each molecule is 10^-20kg. The mean of speed squared is 4m²/s². What is the value of internal energy of the gas? Assume volume of container is 0.02m³.

0.53*10^-20J

0.01*10^-20J

0.8*10^-20J

0.45*10^-20J

Question 10 of 10