Question

In meterbridge the null point is found to be 60 cm from a with x and y as shown when the resistance of 15 ohm is connected with series with y, the null point is formed to be shift by 10 cm towards the end a of the wire find the position of null point if the resistance of 30 ohm with connected in parallel with resistance y ,.....

Answer 1

Answer:

the position of null point if the resistance of 30 ohm with connected in parallel with resistance y is 75 cm from end A.

Explanation:

In meterbridge the null point is found to be 60 cm from a with x and y as shown when the resistance of 15 ohm is connected with series with y, the null point is formed to be shift by 10 cm towards the end a of the wire.

Now, X/Y= 60r/(100-60r) [ r= resistance per cm]........(1)

                = 3/2

Now, the resistance of 15 ohm is connected with series with y,

X/Y+15= 50r/(100-50r)

            = 1

X= Y+15.........(2)

Now, putting the value of X in (1)

Y+15/Y= 3/2

3Y=2Y+30

Y= 30 ohm

Now putting the value of Y in (2)

X= 45 ohm

the resistance of 30 ohm with connected in parallel with resistance y the new value of resistance between B and C is Y'

Y'= 30x30/30+30

  = 15 ohm

Let null point is at a distance of l cm

X/Y'=lr/(100-l)r

45/15= l/(100-l)

3 =l/(100-l)

4l= 300

l = 75 cm

Answer 2

Answer:

here's the answer of this question

please mark as brainlist