Physics – Class 11 Mock Test 10

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Question 1 of 10

1. A ball is hanging from a thread. It is given some speed such that the ball makes a complete circle under the influence of gravity. The projection of the ball on the x-axis will be an SHM. True or False?

True

False

Question 1 of 10

Question 2 of 10

2. Why is the speed of longitudinal waves sound in solids greater than that in liquids?

Gases have lesser density

Solids have greater bulk modulus and density than gases but increase in bulk modulus dominantes over increase in density

Solids have lesser bulk modulus

Gases don’t have lesser particles in a given volume and therefore transfer sound energy slowly

Question 2 of 10

Question 3 of 10

3. The angular speed of a body in uniform circular motion is the same as the angular frequency of SHM of its projection. True or False?

True

False

Question 3 of 10

Question 4 of 10

4. An observer is standing stationary in air moving at a speed of 2m/s. A source of frequency 20Hz is moving in the direction of wind with speed 10m/s towards the observer. What will be the frequency as heard by the observer? Speed of sound in air is 330m/s.

19.40Hz

20.62Hz

22.63Hz

21.68Hz

Question 4 of 10

Question 5 of 10

5. A particle is undergoing a SHM of amplitude 10cm. What should be the minimum value of acceleration at an extreme position for maximum speed at centre to be 5m/s?

20m/s²

5m/s²

250m/s²

Question 5 of 10

Question 6 of 10

6. The graph of acceleration vs time for a SHM is given. FInd the equation of position of the particle as a function of time. Assume that the particle is oscillating on the x-axis about the origin. And consider RHS of origin to be positive & LHS to be negative.

0.81sin(πt)

-8cos(πt)

8cos(πt)

-0.81sin(πt)

Question 6 of 10

Question 7 of 10

7. A particle is executing SHM and currently going towards the amplitude. If it is at A/2, what is the relation between the direction of velocity and acceleration?

Velocity is towards mean position & acceleration is towards the amplitude

Both vectors point towards the mean position

Both vectors point towards the amplitude

Velocity is towards amplitude & acceleration is towards mean position

Question 7 of 10

Question 8 of 10

8. A pipe is open at both ends. What should be its length such that it resonates a 10Hz source in the 2nd harmonic? Speed of sound in air = 340m/s.

68m

17m

51m

34m

Question 8 of 10

Question 9 of 10

9. What is the amplitude of motion for x = 2sin(2t) + 4sin²t ?

The given equation is not that of an SHM

2√2 m

4 m

2 m

Question 9 of 10

Question 10 of 10

10. A sinusoidal wave has an amplitude of 2cm. It is travelling in the negative x-direction. The distance between two crests is 2cm. The angular frequency is πs^-1. What is the displacement of the particle at x = 20.5cm, at t = 10s? Assume that at t=0 & x=0 the particle was at the mean position and going downwards. ‘x’ &’y’ are in cm.

1cm

-2cm

-1cm

0cm

Question 10 of 10