Question

The current in the circuit shown is 2.0 A.

What is the value of R3?

A) 10 Ω
B) 15 Ω
C) 20 Ω
D) 55 Ω

Answer 1

The value of R3 is A) 10 Ω

Answer 2

Resistor R₃ = 10 Ω

Step-by-step explanation:

It is given that,

Current flowing in the circuit, I = 2 A

Resistors R₁ = 2 Ω

Resistor R₂ = 3 Ω

Voltage, V = 30 V

We have to find the value of R₃. All three resistors are connected in series. In series combination, the current flowing through the all resistors is same. Firstly, calculating equivalent resistance of three resistors as :

`R_(eq)=R_1+R_2+R_3`

`R_(eq)=2\ \Omega+3\ \Omega+R_3`

`R_(eq)=5\ \Omega+R_3`..............(1)

Using Ohm's law :
`V=IR_(eq)`

`30\ V=2\ A* (5 + R_(3))`

On solving above equation :
`R_3=10\ \Omega`

Hence, the correct option is (A) " 10 Ω "