Large transformers, when used for some time, become very hot and are cooled by circulating oil. The heating of the transformer is due to

A) the heating effect of current alone
B) hysteresis loss alone
C) both the heating effect of current and hysteresis loss
D) intense sunlight at noon

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out of the following, which is not emitted by radioactive substance?

A) Electrons
B) Electromagnetic radiations
C) Alpha particles
D) Neutrons

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Light year is a unit of

A) time
B) distance
C) light
D) intensity of light

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Pick out the scalar quantity

A) force
B) pressure
C) velocity
D) acceleration

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Mirage is due to

A) unequal heating of different parts of the atmosphere
B) magnetic disturbances in the atmosphere
C) depletion of ozone layer in the atmosphere
D) equal heating of different parts of the atmosphere

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