a resistor of unknown value R is connected in parallel with a resistance of 15 ohms. this combination is connected in series with a resistance of 30 ohms. the current is then connected across a 160v DC supply. determine the value of the resistor R when a 4A current is drawn from the supply

Answer 1

To determine the value of the resistor R, we can use the total resistance formula for resistors connected in series and parallel:

1/Rt = 1/R1 + 1/R2

Where Rt is the total resistance, R1 is the resistance of the resistor connected in parallel with R, and R2 is the resistance in series with the parallel combination.

Given that R1 = 15 ohms and R2 = 30 ohms, we can substitute these values into the formula:

1/Rt = 1/15 + 1/R

1/30 = 1/15 + 1/R
1/R = 1/30 - 1/15
1/R = (2 - 1) / 30
1/R = 1/30

Now, we can find the value of R:

R = 30 ohms

Therefore, the value of the resistor R is 30 ohms.