Question 1

What is the SI unit of wave amplitude?

Accepted Answer

Amplitude is the maximum displacement of a particle from its mean position, measured in meters.

Question 2

A wave completes 4 oscillations in 2 seconds. What is its time period?

Accepted Answer

Time period T = total time / number of oscillations = 2 / 4 = 0.5 s.

Question 3

A wave travels with a frequency of 50 Hz and wavelength of 0.4 m. What is the wave velocity?

Accepted Answer

Wave velocity v = frequency × wavelength = 50 × 0.4 = 20 m/s.

Question 4

Which of the following is a characteristic of transverse waves?

Accepted Answer

In transverse waves, particle displacement is perpendicular to wave propagation direction, unlike longitudinal waves where displacement is parallel.

Question 5

A sound wave has a wavelength of 2 m and travels at 340 m/s in air. What is its frequency?

Accepted Answer

Frequency f = velocity / wavelength = 340 / 2 = 170 Hz.

Question 6

Two waves with frequencies 60 Hz and 40 Hz interfere. What is the beat frequency?

Accepted Answer

Beat frequency = |f₁ - f₂| = |60 - 40| = 20 Hz.

Question 7

A wave travels a distance of 60 m in 3 seconds. If its wavelength is 2 m, what is its frequency?

Accepted Answer

Wave speed = 60/3 = 20 m/s; using v = fλ, frequency f = 20/2 = 10 Hz.

Question 8

A longitudinal wave has a frequency of 100 Hz and travels at 1500 m/s in water. Calculate its wavelength.

Accepted Answer

Using v = fλ, wavelength λ = 1500/100 = 15 m.

Question 9

Which phenomenon occurs when two waves of the same frequency traveling in opposite directions meet?

Accepted Answer

When waves of equal frequency traveling in opposite directions superpose, standing waves are formed due to constructive and destructive interference.

Question 10

A sound wave travels through air with a frequency of 500 Hz and a wavelength of 0.68 m. Calculate the speed of sound in air.

Accepted Answer

Speed of wave = frequency × wavelength = 500 × 0.68 = 340 m/s.

Question 11

Which of the following correctly defines the wavelength of a wave?

Accepted Answer

Wavelength is the spatial distance between two consecutive points in the same phase of oscillation.

Question 12

A wave has a frequency of 20 Hz and travels at 400 m/s. What is its wavelength?

Accepted Answer

Using v = fλ, we get λ = v/f = 400/20 = 20 m.

Question 13

The time period of a wave is 0.02 seconds. What is its frequency?

Accepted Answer

Frequency = 1/Time Period = 1/0.02 = 50 Hz.

Question 14

A transverse wave on a string has an amplitude of 5 cm. What is the maximum distance a particle on the string moves from its equilibrium position?

Accepted Answer

Amplitude is the maximum displacement of a particle from its mean position, which is 5 cm.

Question 15

A sound wave travels through air at 340 m/s with a frequency of 680 Hz. What is the wavelength of this sound wave?

Accepted Answer

Using v = fλ, wavelength λ = v/f = 340/680 = 0.5 m.

Question 16

Two waves of the same frequency and amplitude travel in opposite directions along a string. What type of wave pattern is formed?

Accepted Answer

Superposition of two identical waves traveling in opposite directions creates a stationary (standing) wave with nodes and antinodes.

Question 17

A tuning fork vibrates at 256 Hz and produces a sound wave with wavelength 1.35 m in air. Calculate the speed of sound in the medium.

Accepted Answer

Speed of sound v = fλ = 256 × 1.35 = 345.6 m/s.

Question 18

A vibrating string of length 0.8 m is fixed at both ends and vibrates in its second harmonic mode. What is the number of half-wavelengths in the string?

Accepted Answer

In the second harmonic (first overtone), the string contains exactly 2 half-wavelengths between the two fixed ends.

NDA Waves

Waves — Practice Questions