Two unknown resistances are connected in two gaps of a meter bridge, null point is obtained at 40 cm from left end. A 30 \Omega resistance is connected in series with the smaller of the resistance, the null point shifts by 20 cm to the right end.

The value of smaller resistance in \Omega is

  1. 48

  2. 12

  3. 36

  4. 24

Answers (1)
S Sayak

Let the two resistors have resistances x \Omega and y \Omega 

\frac{x}{40}=\frac{y}{60}

\frac{x+30}{60}=\frac{y}{40}

Solving above equations we get x = 24 and y = 36

The value of smaller resistance in \Omega is 24.

Option 4 is correct

Exams
Articles
Questions