1. A student carried out an experiment using a laser beam incident on double slits with negligible widths. An interference pattern is observed on a distant screen.

Which of the following is correct for the pattern observed on the screen when the slits of non-negligible widths are used with the same slit separation?

I. It is modulated with the single slit diffraction effect
II. Central maximum is brighter
III. Fringe spacing is larger

2. A mass $M$ hangs in equilibrium on a spring. The mass is pulled down 10$cm$ below the equilibrium position and released. It oscillates vertically about the equilibrium position performing simple harmonic motion.

If it takes 0.5 $s$ after release to return to its equilibrium position, which of the following is true for its first oscillation?

3. In a single slit diffraction experiment, incident light passes through an aperture and a diffraction pattern is observed on a distant screen. $X$ is a point on the screen between the second-order minimum and the first-order minimum. $Y$ is a point at the centre of the principal maximum.

Which one of the following could be the ratio of the intensity of light on X to the intensity of light on $Y$?

4. A mass-spring system executes simple harmonic motion with a period $T$ in a vertical plane. What is the period when the oscillating mass is doubled and the system is brought to a planet where the gravitational field strength at the surface is halved?

5. For an object undergoing simple harmonic oscillation, the graphs show the variation of two quantities for the object with time $t$.

Which two quantities could be represented by these graphs?

6. A light ray is incident on a semicircular glass block from the air. The glass has a greater refractive index than air. Which diagram correctly represents a possible path of the light ray as it enters and leaves the block?

A.				B.
C.				D.

7. A laser beam passes through a narrow slit and incident on a screen. A diffraction pattern is observed on the screen. The variation of intensity $I$ of light on the screen with distance $x$ is seen in the graph below.

Which of the following graphs best represents intensity distribution with distance when the slit is replaced by one of greater width? The original distribution is shown with a dashed line.

A.				B.
C.				D.

8. An object on a horizontal spring performs simple harmonic motion. The position of the object as a function of time is given by x=5 cos⁡(2t).

Which of the following expressions gives the acceleration of this object as a function of time?

9. Incident light of wavelength $600nm$ is emitted towards two slits separated by $1\mu m$. The interference pattern is observed on a wall. The distance between two adjacent maxima is $1.2m$. What is the distance of the wall from the slits?

10. A beam of monochromatic light is incident on a single slit. After passing the slit, a diffraction pattern is observed on a screen of distance $D$ to the slit.

Which of the following is correct for the diffraction pattern observed on the screen when the D is doubled?

11. A parallel beam of light with a wavelength of $500nm$ passes through a narrow slit with a slit width of $2\mu m$. The angle of diffraction for the first minimum is θ. What is the new angle of diffraction for the first minimum when the slit width is changed to $4\mu m$ and the wavelength of the light is now $250nm$?

12. A traveling source produces sound waves nearby a child. The wavefronts of the sound waves and the position of a child are seen in the figure below.

The frequency of the generated sound waves is $f$. Which of the following is correct for both the direction of motion of the source and the observed frequency of the sound waves by the child?

13. Two identical objects $P$ and $Q$ are connected to identical springs. Both $P$ and $Q$ are performing simple harmonic motion (SHM) around equilibrium level $O$.

The diagram shows positions of $P$ and $Q$ at time $t=0$. Which graph shows how kinetic energy of $P$ and $Q$ vary with time $t$?

A.				B.
C.				D.

14. Water drips onto a pond every 3.0 seconds. The speed of water waves in the pond has been measured to be 1.2ms^−1. What is the wavelength of water waves generated because of the drops?

15. Two simple pendulums with lengths $16L$ and $9L$ have masses $4M$ and $3M$ respectively. The period of the mass of $M$ is T. What is the period of mass of $3M$?

16. A spring-mass system executes simple harmonic motion with an amplitude of $20cm$ and maximum elastic potential energy of $100J$. What is the displacement of the mass when the elastic potential energy of the system is $25J$?

18. A parallel beam of light passes through two parallel slits and an interference pattern is formed on a distant screen. The fringe separation is too small to measure. Which of the following would increase the fringe separation?

I. Increase the distance between slits and screen
II. Replace the light source with one with a longer wavelength
III. Increase the slit separation

19. Three monochromatic light sources, $K$, $L$, and $N$, are incident on a single slit separately. The diagram shows obtained diffraction patterns on the screens for each light source along with the relative widths of their central maxima.

In which option are the possible colors of the light sources given correctly?

20. A taut string on a guitar is fixed at both ends.

21. An object with a mass of $m$ is connected to a spring on a frictionless horizontal surface.

The object is displaced by $x$ from its equilibrium point O to point $A$ and executes simple harmonic motion with a period of $T$. Which of the following are true if the object is displaced by $2x$?

I. The angular frequency of the oscillation will be less.
II. Total energy of the object will be greater.
III. The average speed of the object will not change.

22. A train is traveling at 30ms^−1 towards a stationary observer. It sounds a horn of frequency $450Hz$.

Which of the following statements is true about the observed frequency compared with the emitted frequency as the train approaches?

23. A boy tied two identical ropes to a fixed wall for a fitness exercise. He shakes the ropes to form waves.

A point on the right rope oscillates with a period of $0.4s$. A point on the left rope oscillates with a period of $0.2s$.

What is the ratio = wavelength of right rope/wavelength of left ?

24. A thin beam of monochromatic blue light is incident upon a single slit barrier. The emerging light then passes through a double slit arrangement and falls on a screen some distance away.

An interference pattern is observed on the screen. In order to increase the distance between adjacent fringes, which of the following actions would be appropriate?

25. A simple pendulum undergoes simple harmonic motion. The graph shows the variation of a quantity $y$ with horizontal displacement x from the equilibrium position.

Which of the following quantities could be represented by quantity y?