Ohm’s law is not applicable to____________?

Instantaneous power in inductor is proportional to the

A. product of the instantaneous current and rate of change of current.
B. square of instantaneous current.
C. square of the rate of change of current.
D Temperature of the inductor.

The instantaneous voltage across the inductor is expressed as the product of inductance and rate of change of current through it. Power is expressed as the product of current and voltage. Hence instantaneous power in an inductor is proportional to the product of instantaneous current and rate of change of current through it.

 If P is the power of a star connected system then what will be power of an equivalent delta connected system?A. P
B. 3P
C. P/3
D. None of the above

Assume 3 numbers of pure resistive loads each of value R.
When these loads are connected in delta the power in each resistor is V^2/R and the total power is 3×V^2/R.
When these loads are connected in star the voltage applied across each = V/(sqrt of 3). Power in each load becomes = V^2/(3×R) . and the total load is =(3×V^2)/(3×R)=V^2/R. You can see this is 3 times less than the total power when the loads are connected in delta.
One important point is that the loads should withstand higher voltage (line voltage) and higher current when connected in delta than when they are connected in star
so power in delta is 3 time power correct answer is 3P