20003.Large transformers, when used for some time, become very hot and are cooled by circulating oil. The heating of the transformer is due to
the heating effect of current alone
hysteresis loss alone
both the heating effect of current and hysteresis loss
intense sunlight at noon
20014.It is more difficult to walk on a sandy road than on a concrete road because
sand is soft and concreter is hard
the friction between sand and feet is less than that between concrete and feet
the friction between sand and feet is more than that between concrete and feet
the sand is grainy but concrete is smooth