Question

In a meter bridge, null point is 20 cm, when the known resistance R is shunted by 10Ω resistance, null point is found to be shifted by 10 cm. Find the unknown resistance X.

Answer 1

To find the unknown resistance X in a meter bridge, we can use the formula X = (L1 / L2) * R. Given that the null point is shifted by 10 cm when the known resistance R is shunted by a 10Ω resistance, we can calculate X as 3.33Ω.

Step-by-step explanation:

To find the unknown resistance X in a meter bridge, we can use the formula:

X = (L1 / L2) * R

Here, L1 is the length of wire on one side of the null point, L2 is the length of wire on the other side of the null point, and R is the known resistance.

Given that the null point is shifted by 10 cm when the known resistance R is shunted by a 10Ω resistance, we can calculate L1 and L2 as follows:

L1 = (20 - 10) cm = 10 cm

L2 = (20 + 10) cm = 30 cm

Substituting these values into the formula:

X = (10 / 30) * R

And since R is given as 10Ω, we can calculate X as follows:

X = (10 / 30) * 10Ω = 3.33Ω