9 February, 12:16

# A computer is connected across a 110 V power supply. The computer dissipates 123 W of power in the form of electromagnetic radiation and heat. Calculate the resistance of the computer.

+2
1. 9 February, 14:04
0
81.3ohms

Explanation:

Resistance is known to provide opposition to the flow of electric current in an electric circuit.

Power dissipated by the computer is expressed as;

Power = current (I) * Voltage (V)

P = IV ... (1)

Note that from ohms law, V = IR

I = V/R ... (2)

Substituting equation 2 into 1, we will have;

P = (V/R) * V

P = V²/R ... (3)

Given source voltage = 100V, Power dissipated = 123W

To get resistance R of the computer, we will substitute the given value into equation 3 to have

123 = 100²/R

R = 100²/123

R = 10,000/123

R = 81.3ohms

The resistance of the computer is 81.3ohms
2. 9 February, 15:56
0
98.37 ohms.

Explanation:

Power, P = I * V

Using ohms law,

V = I * R

P = V^2/R

Given:

V = 110 V

P = 123 W

R = 110^2/123

= 98.37 ohms.