Question

2 points Resistance 4 ohm and 6 ohm are connected across the left gap and right gap respectively of a meter bridge. When a 2 ohm resistance is connected in series with 4 ohm in the left gap, the shift in balance point is- O 10 cm O 15 cm 0 20 cm 30 cm Other 16.7 cm​

Answer 1

Answer:

10cm

Explanation:

4/6=l/(100-l)

On solving., l=40cm

2ohm in series, we get 6/6=l/(100-l)

On solving.,l=50cm

Therefore shift=10cm

Answer 2

The correct option to the above question is (A), which is 10cm.

Given: Two resistance = 4Ω, 6Ω

            New resistance added in series = 2Ω

To find: New shift in the balance point

Solution:

A meter bridge is an electrical apparatus using which we can measure the value of unknown resistance.

Let the earlier balance point of the meter bridge be L form 4Ω.

According to meter bridge - 4/6 = L/(100-L)

2/3 = L/100-L

2(100-L) = 3L

200 - 2L = 3L

5L = 200

L = 40cm

Now, the 2Ω is connected across the resistance of 4Ω.

Therefore, the effective resistance on left side will be 6Ω.

Now, let the new balance point be X

6/6 = X/(100-X)

1 = X/(100-X)

100 - X = X

2X = 100

X = 50cm

Therefore, the shift of balance point will be X - L = 50 - 40 = 10cm