Unit 4 Waves General

Which graph correctly shows how the acceleration, a of a particle undergoing SHM varies with its displacement, x from its equilibrium position?

• A

• B

• C

• D

In which of the following regions of the electromagnetic spectrum is radiation of wavelength 600 nm located?

• microwaves

• radio waves

• visible light

• X-rays

Two waves meet at a point in space. Which of the following properties always add together?

• Displacement

• Amplitude

• Speed

• Frequency

One end of a horizontal string is fixed to a wall. A transverse pulse moves along the string as shown.

Which of the following statements are correct for the reflected pulse compared to the forward pulse?

I. It moves more slowly.

II. It has less energy.

III. It is inverted.

• I and II only

• I and III only

• II and III only

• I, II and III

A transverse wave travels from left to right. The diagram below shows how, at a particular instant of time, the displacement of particles in the medium varies with position. Which arrow represents the direction of the velocity of the particle marked P?

• A

• B

• C

• D

The phenomenon of diffraction is associated with

• sound waves only.

• light waves only.

• water waves only.

• all waves.

A pendulum swings back and forth in a circular arc between X and Y.

The pendulum bob is

• always in equilibrium.

• only in equilibrium at X and Y.

• in equilibrium as it passes through the central position.

• never in equilibrium.

A beam of unpolarised light is incident on the surface of a liquid and is partially reflected and partially refracted as shown in the picture.

The reflected light is completely horizontally polarized. Which of the following is the refractive index of the liquid?

• tan 40°

• tan 50°

• $\frac{\sin\ 40\degree}{\sin\ 50\degree}$

• $\frac{\sin\ 40\degree}{\cos\ 50\degree}$

Progressive (travelling) waves S and T have the same frequency and are in the same medium. S has amplitude 2.0 m and T has amplitude 4.0 m. What is the ratio of the intensity of T to the intensity of S?

• $\frac{1}{4}$

• $\frac{1}{2}$

• 2

• 4

Unpolarised light is incident on the surface of a transparent medium. The reflected light is completely plane polarised. The refracted light will be

• unpolarised.

• partially plane polarised.

• completely plane polarised at right angles to the reflected light.

• completely plane polarised parallel to the reflected light.