Question

A circuit elements is placed in a closed box. At time t =0, a constant current generator supplying a current of 1 A is connected across the box. Potential difference across the box varies according to graph shown below. The element in the box is

(a) a resistance of 2Ω

(b) a battery of emf 6 V

(c) an inductance of 2 H

(d) a capacitance of 0.5 F

Answer 1

The correct option is (d) a capacitance of 0.5 F.

Explanation:

Since, on supplying a constant current of 1 A in the circuit element, the potential difference across it is increasing, therefore it should be a capacitor because on supplying the current, the charge as well as the potential will increase. From graph, Charge supplied to the capacitor in 3 *.

q = It

q = 1 x 3

q = 3 C

A charge of 3 C increases the potential difference across the capacitor through (8 - 2) = 5 V

C = Δq/ΔV = 3/6 = 0.5 F