<em>★</em><em> </em><em>«</em><em> </em><em><u>what is sound wave and examples</u></em><em><u> </u></em><em>»</em><em> </em><em>★</em>
- <em>A sound wave is the pattern of disturbance caused by the movement of energy traveling through a medium (such as air, water, or any other liquid or solid matter) as it propagates away from the source of the sound. The source is some object that causes a vibration, such as a ringing telephone, or a person's vocal chords.</em>
<em>hope </em><em>it</em><em> helps</em>
Answer: person C.
Explanation:
1) The frequency of the sound wave is perceived or detected as the pitch of the sound.
And the higher the frequency the the higher the pitch.
2) When a sound source is in motion there is an apparent change in the pitch perceived. This is the Doppler effect, which is defined as the change in the perception of the pitch in virtue of the relative motion between the listener and the emitter of the sound.
If the source of the sound is moving toward the listener, the pitch will be higher that if the sound is at rest. If the source of the sound is moving away from the listener, the pitch will be lower.
That is because the the motion of the emitter increases (or decreases, depending on whether the emitter is moving toward or away the listener) the speed of the sound waves and they arrive more frequently (or less frequently).
Then, since the sound is emitted by the motorbike and it is moving toward the person C, he will hear the highest pitch.
Answer:
Induced emf in the loop is 0.02208 volt.
Induced current in the loop is 0.0368 A.
Explanation:
Given that,
Area of the single loop, 
The initial value of uniform magnetic field, B = 3.8 T
The magnetic field is decreasing at a constant rate, 
(a) The induced emf in the loop is given by the rate of change of magnetic flux.

(b) Resistance of the loop is 0.6 ohms. Let I is the current induced in the loop. Using Ohm's law :

Hence, this is the required solution.
Answer:
The correct answer is option '5': The type of metal from which the plate is made.
Explanation:
According to the principle of photoelectric effect we know that electron's are only emitted from a surface of metal if the frequency of the light is larger than a threshold frequency that depends on the metal and is known as threshold function of the metal. The ejection of the electrons is independent of intensity of the incident light meaning any light of frequency lower than work function will not eject electrons from the metal no matter whatever the intensity of the light, or the surface area or thermal conductivity, time of illumination.