When a potential difference is applied across, the current passing through

Options

A. an insulator at 0 K is zero
B. a semiconductor at 0 K is zero
C. a metal at 0 K is finite
D. a p-n diode at 300K is finite, if it is reverse biased

Answer

A, B, D

Explanation

(a,b,d) At 0K an insulator does not permit any current to flow through it. Option (a) is correct.
At 0K a semiconductor behaves as an insulator. Option (b) is correct.
In reverse biasing at 300 K, a very small current. Flows through a p-n junction diode. Option (d) is correct.
In case of metal, the current flowing will be very-very high because a metal becomes super conductor at 0K. Option (c ) is incorrect.