Physics MCQs
Topic Notes: Physics
MCQs and preparation resources for competitive exams, covering important concepts, past papers, and detailed explanations.
Plato
- Biography: Ancient Greek philosopher (427–347 BCE), student of Socrates and teacher of Aristotle, founder of the Academy in Athens.
- Important Ideas:
- Theory of Forms
- Philosopher-King
- Ideal State
11
Which types of waves exhibit the Doppler effect?
Answer:
both sound and light waves
The Doppler effect is a general wave phenomenon occurring whenever there is relative motion between a wave source and an observer. It causes a shift in the observed frequency of the wave. This effect is observed in mechanical waves, such as sound, as well as in electromagnetic waves, such as light, which is fundamental to understanding astronomical phenomena like the redshift of distant galaxies.
12
Which types of waves exhibit the Doppler effect when there is relative motion between the source and the observer?
Answer:
both sound and light waves
The Doppler effect is a general wave phenomenon. It occurs whenever a wave source moves relative to an observer, causing a shift in the observed frequency. This applies to mechanical waves like sound, as well as electromagnetic waves like light, which is fundamental in fields like astronomy for measuring stellar velocities.
13
How does the perceived frequency change when a sound source moves away from a stationary observer?
Answer:
frequency appears to decrease
When a sound source moves away from a stationary observer, the Doppler effect causes the wavefronts to be spaced further apart as they reach the observer. This increase in wavelength results in a lower perceived frequency, which is heard as a drop in pitch.