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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Of the following properties of a wave, the one that is independent of the other is its

A) amplitude
B) velocity
C) wavelength
D) frequency

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Nuclear sizes are expressed in a unit named.

A) Fermi
B) angstrom
C) newton
D) tesla

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Sound waves in air are

A) transverse
B) longitudinal
C) electromagnetic
D) polarised

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Rectifiers are used to convert

A) Direct current to Alternating current
B) Alternating current to Direct current
C) high voltage to low voltage
D) low voltage to high voltage

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