Question

In an electric resistance of 20 ohms, if the current intensity passing through it

is doubled, its value becomes ........ ohms.
b. 20
d. 40
a. 10
c. 30​

Answer 1

a. 10 ohms.

Step-by-step explanation:

Given;

first electrical resistance, r₁ = 20 ohms

let the first current through the circuit = I₁

let the second current through the circuit, I₂ = 2I₁ (since it is doubled)

then, the new value of the resistance after doubling the current = r₂

the current intensity is given as;

`(dI)/(dt) = I = (v)/(r) \\\\I_1r_1 = I_2r_2\\\\r_2 = (I_1r_1)/(I_2) \\\\r_2 = (I_1 * 20)/(2I_1 ) \\\\r_2 = 10 \ ohms`

Therefore, the new value of the resistance is 10 ohms.