Question

There is a current of 1.0 A in the circuit shown below. What is the resistance of P? a) 1.5Ωb) 2.5 Ωd) 4.5Ωc) 3.5Ω​

Answer 1

Given ,

• 3 Ω , 2.5 Ω and P Ω are connected in series combination with 2 v

• Total current in the circuit is 1.0 amp

We know that , the equivalent resistance in series combination is given by

$\boxed{ \sf{R = R' + R'' + R''' + ....}}$

Thus ,

R = 3 + 2.5 + P

R = (5.5 + P) Ω

Now , the relationship between current and potential difference is given by

$\boxed{ \sf{V = IR}}$

Thus ,

9 = 1.0 × (5.5 + P)

9 = 5.5 + P

P = 4.5 Ω

∴The correct option is (C) i.e 4.5 Ω