Short Answer Typei) A particular type of high energy invisible electromagnetic rays help us to study the structure of crystals. Name these rays and give another important use of these rays.
ii) How does the speed of light in glass change on increasing the wavelength of light?i) i) X-rays,
Another important use of these rays: To take X-rays of human body.
ii) Speed of light in glass increases on increasing the wavelength of light. Both speed and wavelength is directly proportional to each other.
A man standing in front of a vertical cliff fires a gun. He hears the echo after 3 seconds. On moving closer to the cliff by 82.5 m, he fires again. This time, he hears the echo after 2.5 seconds. Calculate:
i) The distance of the cliff from the initial position of the man.
ii) The velocity of the sound.
The V-I graph for a series combination and for a parallel combination of two resistors as shown in the figure:
Calculate the value of the resistance which must be connected to a 15 ohm resistance to provide an effective resistance of 6 ohm.
Of the three connecting wires in a household circuit:
i) Which two of the wires are at the same potential?
ii) In which of the three wires should the switch be connected?
i) What is meant by earthing of an electrical appliance? Why is it essential?
ii) What will be the effect on the working of an electric bell if instead of a direct current, an alternating current is used?i) State two factors on which the strength of an induced current depends upon.
ii) When a solenoid that is carrying current is freely suspended, it comes to rest along a particular direction. Why does this happen?Some hot water was added to three times its mass of cold water at 10 degree Celsius and the resulting temperature was found to be 20 degree C. What was the temperature of the hot water?
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