Question

A 3 Ohm resistor is connected in series with a 5 Ohm resistor to a battery. Which of the following statements are true (there can be more than one)?

a) The power loss in the 5 Ohm resistor is greater.

b) The current through the 5 Ohm resistor is lower.

c) The potential difference across both resistors is the same.

d) The potential difference across the 3 Ohm resistor is higher.

e) The current flowing in each resistor is the same.

Answer 1

Suppose Potential difference across battery is V.

Then equivalent resistance, when two resistors are in series, will be:

Req = R1 + R2 = 3 + 5 = 8 ohm

Using ohm's law:

Ieq = V/Req = V/8

Now Remember that if resistors are in series with battery then current through each resistor will be same and equal to total current. (Since current only has one path to travel in series circuit). So

Current through 3 ohm = Current through 5 ohm = Ieq = V/8

Option E is Correct.

Also, o

Potential difference across 3 ohm will be: V1 = I1*R1

V1 = (V/8)*3 = 3V/8

Potential difference across 5 ohm will be: V2 = I2*R2

V2 = (V/8)*5 = 5V/8

So, V2 > V1

Both options C and D are incorrect.

Power loss across 3 ohm resistor will be:

P1 = I1^2*R1 = (V/8)^2*3 = 3V^2/64

Power loss across 5 ohm resistor will be:

P2 = I2^2*R2 = (V/8)^2*5 = 5V^2/64

So, P2 > P1

Option A is Correct.

So correct options are: A and E.

Let me know if you've any query.