Question

In the figure shown, all the resistors have the same resistance. If the ideal ammeter reads 2 A and the ideal voltmeter reads 15 V, what is the resistance of each resistor?

• A. $\frac{5}{2}$ohm
• B. $\frac{15}{4}$ohm
• C. $\frac{15}{2}$ohm
• D. $\frac{5}{3}$ohm

Answer 1

The correct option is A $\frac{5}{2}$ohm

Here, all the resistors have the same resistance and the ideal ammeter reads 2 A and the ideal voltmeter reads 15 V.

Hence, twice the current flows through the single resistor than current flowing through each of the resistors in parallel.

Therefore, $\frac{2}{3}$ or 10V of the total potential drop of 15 V appears across the single resistor, and $\frac{1}{3}$ or 5V, appears across each parallel resistor.

Since the current through one parallel resistor is 2 A, its resistance must be $\frac{5}{2}\Omega$