A 120-Ω laboratory resistor is rated at 0.25 W. How much current can safely flow through the resistor?

0.0436 A

Explanation:

Current: This can be defined as the rate of flow of electric charge in a circuit. The S. I unit of current is Ampere (A).

The expression of current is given as

P = I²R

Where P = power, I = current, R = Resistance.

Make I the subject of the equation,

I = √ (P/R) ... Equation 1

Given: P = 0.25 W, R = 120 Ω

Substitute into equation 1

I = √ (0.25/120)

I = √ (0.00208)

I = 0.0456 A.

Hence the current that can safely pass through the resistor = 0.0436 A