Upon increasing the temperature, the resistance of a wire :
(a) decreases
(b) does not change
(c) increases
(d) first increases then decreases

(c) increases

Reason — If the temperature of the wire increases, ions in it vibrate more violently. As a result, the number of collisions increases and hence the resistance of wire increases (i.e., the resistance of the wire increases with the increase in it’s temperature.