Question

Two resistances of 1 ohm are connected in series and this combination is connected across a 5V Battery. Let current flowing be $I_1$.
If value of one of the two resistances change to 1.5 ohm while keeping other constant and same battery source. Let new current be $I_2$.
$\frac{I_2}{I_1}$ =

• A. 0.9
• B. 0.8
• C. 0.7
• D. 0.6

Answer 1

The correct option is B 0.8

Equivalent Resistance for two resistance in series

$R=R_1+R_2$

By Ohm's Law, V = IR

5 = I1 x (1+1)

I1 = 2.5 A

Similarly,

5 = I2 x (1+1.5)

I2 = 2 A

I2/I1 = 2/2.5 = 0.8