Question

The correct expression for the instantaneous current in a resistive circuit is?

(a) i=Vm(sint)/R

(b) i=Vm(cost)/R

(c) i=V(sint)/R

(d) i=V(cost)/R

Answer 1

Correct choice is (a) i=Vm(sint)/R

The best I can explain: The instantaneous voltage can be written in terms of the maximum voltage in the following manner:

v=Vm(sint)

Since i=v/R, we can write,  i=Vm(sint)/R.