Waves Basics — Set 2
Physics · तरंगों की मूल बातें · Questions 11–20 of 60
Bending of waves around the edges of an obstacle is called?
Correct Answer: C. Diffraction
Diffraction is correct because waves spread into the shadow region behind obstacles. It is more noticeable when obstacle size is comparable to wavelength. Sound diffracts more around doors than light does.
The superposition principle states that when waves overlap, the resultant displacement is the?
Correct Answer: C. Sum of displacements
Sum of displacements is correct because displacements add algebraically during overlap. This leads to interference patterns in many cases. The waves continue after overlap as if they passed through.
In a standing wave, points where displacement is always zero are called?
Correct Answer: D. Nodes
Nodes are correct because the medium never moves at those points. Antinodes are points of maximum displacement. Standing waves form by interference of two opposite traveling waves.
The beat frequency produced by two sound sources of frequencies f1 and f2 is?
Correct Answer: D. |f1 − f2|
|f1 − f2| is correct because beats come from slow amplitude variation. When frequencies are close, the difference frequency is small and audible as beats. Beats are used for tuning musical instruments.
The Doppler effect is the apparent change in observed?
Correct Answer: C. Frequency due to relative motion
Frequency change is correct because motion between source and observer alters wavefront spacing. Approaching increases observed frequency and receding decreases it. Doppler effect is common for sound sirens.
Polarization is a phenomenon associated with?
Correct Answer: D. Transverse waves
Transverse waves are correct because they have a vibration direction perpendicular to motion. Longitudinal waves do not show polarization in the same way. Polarization is a key property of light.
The speed of electromagnetic waves in vacuum is approximately?
Correct Answer: D. 3 × 10^8 m/s
3 × 10^8 m/s is correct because electromagnetic waves travel at the speed of light in vacuum. This value is a fundamental constant used in physics. In materials, light speed is usually lower than in vacuum.
In a longitudinal wave, the particles of the medium vibrate?
Correct Answer: A. Parallel to the direction of propagation
Parallel vibration is correct because compressions and rarefactions form along the travel direction. This is the defining feature of longitudinal waves. Sound in air is a common longitudinal wave.
A wavefront is the surface joining points that have the same?
Correct Answer: B. Phase
Phase is correct because all points on a wavefront oscillate in step. Wavefronts help visualize the propagation of waves in space. Rays are drawn perpendicular to wavefronts in simple models.
The colored patterns seen in thin soap bubbles are mainly due to?
Correct Answer: D. Interference
Interference is correct because light reflects from the two surfaces and overlaps. Different path differences strengthen or weaken different colors. This is called thin film interference.