Question

A 39-Ω resistor is connected across a 45-V battery. A. What is the current in the circuit? b. How much energy is used by the resistor in 5. 0 min?

Answer 1

Answer with explanation

a) Formula to find the current that passes through a circuit is :

Voltage = Current × Resistance

Given that,

Voltage = 45V

Resistance = 39Ω

Current =?

Let us find it now.

V = I × R

45V = I × 39Ω

Divide both sides by 39.

1.153A = I = Current

b) Formula to find the energy is:

Energy = voltage × current × time

            = 45V × 1.153A × ( 5 × 60)s

            = 15565.5 J

            = 15.5655kJ