Short Answer TypeHow does the value of the angle of deviation produced by a prism change with an increase in the:
i) value of angle of incidence,
ii) wave-length of the incident lighti) As the angle of incidence increases, initially angle of deviation decreases and later it increases after achieving to a minimum value.
ii) As the wavelength of the incident light increases, angle of deviation decreases with the increase in the wavelength of light. 
An ultrasonic wave is sent from a ship towards the bottom of the sea. It is found that the time interval between the sending and the receiving of the waves is 1.5 second. Calculate the depth of the sea if the velocity of sound in sea water is 1400 m/s.
A stringed musical instrument, such as the sitar, is provided with a number of wires of different thickness. Explain the reason for this.
What is meant by noise pollution? Write the name of one source of sound that causes noise pollution.
Calculate the minimum distance at which a person should stand in front of a reflecting surface so that he can hear a distinct echo.
i) Name the characteristics of sound which enables a person to differentiate between two sounds with equal loudness but having different frequencies.
ii) Define the characteristic named by you in (i)
iii) Name the characteristics of sound which enables a person to differentiate between two sounds of the same soundness and frequency but produced by different instruments.
The equivalent resistance of the following circuit diagram is 4 ohm. Calculate the value of X.
Diagrammatically, illustrate how you would connect a key, a battery, a voltmeter, an ammeter, an unknown resistance R and a rheostat so that it can be used to verify ohm's law.
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