Question :

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

Answer : C

Description :



Related Questions - 1


Out of the following pairs, choose the pair in which the physical quantities do not have identical dimension?


A) Pressure and Young modules
B) Planck constant and Angular momentum
C) Impulse and moment of force
D) Force and rate of change of linear momentum

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Related Questions - 2


Radiocarbon is produced in the atmosphere as a result of


A) collision between fast neutrons and nitrogen nuclei present in the atmosphere
B) action of ultraviolet light from the sun on atmospheric oxygen
C) action of solar radiations particularly cosmic rays on carbon dioxide present in the atmosphere
D) lightning discharge in atmosphere

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Sound waves in air are


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

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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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Related Questions - 5


The absorption of ink by blotting paper involves


A) viscosity of ink
B) capillary action phenomenon
C) diffusion of ink through the blotting
D) siphon action

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