#### Oscillations Book Back Questions

11th Standard

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Physics

Time : 00:45:00 Hrs
Total Marks : 30
5 x 1 = 5
1. In a simple harmonic oscillation, the acceleration against displacement for one complete oscillation will be

(a)

an ellipse

(b)

a circle

(c)

a parabola

(d)

a straight line

2. A simple pendulum is suspended from the roof of a school bus which moves in a horizontal direction with an acceleration a, then the time period is

(a)

$T\alpha \frac { 1 }{ { g }^{ 2 }+{ a }^{ 2 } }$

(b)

$T\alpha \frac { 1 }{ \sqrt { { g }^{ 2 }+{ a }^{ 2 } } }$

(c)

$T\alpha \sqrt { { g }^{ 2 }+{ a }^{ 2 } }$

(d)

$\quad T\alpha \left( { g }^{ 2 }+{ a }^{ 2 } \right)$

3. A spring is connected to a mass m suspended from it and its time period for vertical oscillation is T. Th e spring is now cut into two equal halves and the same mass is suspended from one of the halves. Th e period of vertical oscillation is

(a)

T'= $\sqrt{2}$T

(b)

$T'=\frac { T }{ \sqrt { 2 } }$

(c)

T'=$\sqrt{2T}$

(d)

$T'=\sqrt { \frac { T }{ 2 } }$

4. An ideal spring of spring constant k, is suspended from the ceiling of a room and a block of mass M is fastened to its lower end. If the block is released when the spring is un-stretched, then the maximum extension in the spring is

(a)

4$\frac { Mg }{ k }$

(b)

$\frac { Mg }{ k }$

(c)

2$\frac { Mg }{ k }$

(d)

$\frac { Mg }{ 2k }$

5. A hollow sphere is filled with water. It is hung by a long thread. As the water flows out of a hole at the bottom, the period of oscillation will

(a)

first increase and then decrease

(b)

first decrease and then increase

(c)

increase continuously

(d)

decrease continuously

6. 3 x 2 = 6
7. Compute the position of an oscillating particle when its kinetic energy and potential energy are equal.

8. What is meant by force constant of a spring?.

9. A piece of wood of mass m is floating erect in a liquid whose density is ρ. If it is slightly pressed down and released, then executes simple harmonic motion. Show that its time period of oscillation is

10. 3 x 3 = 9
11. Consider two springs with force constants 1 N m−1 and 2 N m−1 connected in parallel. Calculate the effective spring constant (kp) and comment on kp.

12. If the length of the simple pendulum is increased by 44% from its original length, calculate the percentage increase in time period of the pendulum.

13. Write down the kinetic energy and total energy expressions in terms of linear momentum, For one-dimensional case.

14. 2 x 5 = 10
15. Show that for a simple harmonic motion, the phase difference between
a. displacement and velocity is $\frac{\pi}{2}$radian or 90°.
b. velocity and acceleration is  $\frac{\pi}{2}$radian or 90°.
c. displacement and acceleration is $\pi$  radian or 180°.

16. Explain in detail the four different types of oscillations.