Waves quiz

Sound waves in air are:

The speed of sound is greatest in:

At a node of a standing wave, the amplitude is:

The beat frequency of two sources of frequencies f1 and f2 is:

A pipe closed at one end produces:

The speed of a transverse wave on a string is proportional to:

At constant temperature, the speed of sound in air:

The relation between wave speed, frequency and wavelength is:

Waves on a stretched string are:

The phase difference between two points lambda/4 apart on a progressive wave is:

Define amplitude, wavelength and frequency of a wave. (2 marks)

State the principle of superposition of waves. (2 marks)

What is meant by a progressive wave? (2 marks)

Why does the speed of sound increase with temperature? (2 marks)

A man hears the echo of his clap from a cliff after 2 s. Find the distance of the cliff. (2 marks)

What are normal modes of vibration? (2 marks)

Distinguish between a node and an antinode. (2 marks)

Why does a wave pulse reflected from a fixed end get inverted? (2 marks)

How are beats used to tune musical instruments? (2 marks)

Why does the speed of sound in a gas not depend on pressure at constant temperature? (2 marks)

A steel wire 0.72 m long has a mass of 5.0 x 10^-3 kg. If it is under a tension of 60 N, find the speed of transverse waves on it. (3 marks)

Find the fundamental frequency of an open pipe 0.5 m long. Take v = 340 m/s. (3 marks)

A tuning fork of unknown frequency produces 5 beats per second with a fork of 300 Hz. When the unknown fork is loaded with a little wax, the beats decrease. Find its frequency. (3 marks)

The wave y = 0.02 sin(4x - 200t) travels on a string. Find its speed and direction. (3 marks)

A wave of frequency 500 Hz has a speed of 360 m/s. Find the distance between two points that are 60 degrees out of phase. (3 marks)

Read the passage and answer the questions. A guitar string 0.65 m long is fixed at both ends. Waves travel on it at 520 m/s. (i) Find the wavelength of the fundamental mode. (ii) Find the fundamental frequency. (iii) How can the player raise the pitch of the string? (5 marks)

Read the passage and answer the questions. A flute behaves like a pipe open at both ends. One flute is 0.34 m long. Take v = 340 m/s. (i) Find its fundamental frequency. (ii) Find the frequency of its second harmonic. (iii) How does the pitch change on a hot day? (5 marks)

Read the passage and answer the questions. A sitar player tunes a string against a 440 Hz tuning fork and hears 3 beats per second. (i) What are the possible frequencies of the string? (ii) She tightens the string slightly and the beats increase. Which frequency was correct? (iii) What should she do to tune the string? (5 marks)

Read the passage and answer the questions. A student sends a pulse along a rope tied firmly to a wall. (i) What type of wave is the pulse? (ii) How does the reflected pulse differ from the incident pulse? (iii) What happens if the rope end is free to slide on a vertical rod? (5 marks)

Read the passage and answer the questions. A bat emits ultrasonic waves of frequency 50 kHz in air at 340 m/s. (i) Find the wavelength of the waves. (ii) An echo returns from an insect after 0.01 s. Find the distance of the insect. (iii) Why do bats use such high frequencies? (5 marks)

Explain transverse and longitudinal waves with examples, and describe the displacement relation for a progressive wave. (6 marks)

Derive the relation v = f lambda = omega/k, and explain the speed of a transverse wave on a stretched string. (6 marks)

Explain the principle of superposition. Describe the reflection of waves at a rigid boundary and at an open boundary. (6 marks)

Explain the normal modes of vibration of air columns in pipes closed at one end and open at both ends, with diagrams. (6 marks)

Explain the phenomenon of beats and derive an expression for the beat frequency. (6 marks)