Why is the use of A.C. voltage preferred over D.C. voltage? Give two reasons.

Why aluminium metal is preferred to copper for making cooking utensils? Give two reasons.

Why hcp and ccp are preferred over bcc packing ?

Modern telescopes prefer using suitable mirrors over using suitable lenses. Give two reasons of this preference.

In a series resonant circuit, the a.c. voltage across resistance R, inductance L and capacitance C are 5 V. 10 V and 10 V respectively. The a.c. voltage respetively. The a.c. voltage applied to the circuit will be

Why is 'Saheli a preferred contra-ceptive by women ( any two reasons)?

Why transformer cannot be used the step up D.C. voltage?

What is Colostrum ? Why it is preferred over normal milk ?