Question

Alternating current can not be measured by dc ammeter because(a) ac cannot pass through dc ammeter(b) Average value of complete cycle is zero(c) ac is virtual(d) ac changes its direction

Answer 1

the answer is B is alternating current is a function of sin or cos and the average of Sin A cos is zero therefore the reading of the DC ammeter will be zero as DC ammeter shows the average current

Answer 2

answer : option (b) average value of current for a complete cycle is zero.

explanation : The full cycle of alternating current is separated in two halves. for one half , current is positive and for second half, current is negative. but the magnitude of current in case of both half cycle will be same. so, the net value of current equals to zero.

in case of the half cycle, the value of current is different at different points . but we know, in case of dc circuit, It only flows in one direction in the circuit, so the current flows through it in constant magnitude.

That's why , Alternating current can not be measured by dc ammeter because average value of current for ac is zero.