Question

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.

Answer 1

Answer:

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.

Answer 2

Answer:

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