Question

A circuit contains three resistors connected in parallel. The value of R1 is 2 K , the value or R2 is 6 K , and the value of R3 is 10 K . If the supplied voltage is 100 VDC, what is the total power in the circuit?

A. 2.18 W
   
B. 8.18 W
   
C. 7.67 W
   
D. 4.24 W

Answer 1

The value of total resistance of resistors connected in parallel is calculated through the equation,

R = 1 / (1/R1 + 1/R2 + 1/R3 + 1/Rn)

Substituting the known values,

R = 1 / (1/2 + 1/6 + 1/10)
R = 30/23 ohms

The formula for power with the use of resistance and voltage is,

P = V² / R

Substituting,
P = (100 V)² / (30/23 ohms)
P = 7.67 kW

Thus, the answer to this item is letter C.