Question

Arm resistance of wheatstone bridge are R1=200ohm
R2=400ohm

Answer 1

Ques:

In a Wheatstone bridge (see fig.), Resistances P and Q are approximately equal. When R=400Ω, the bridge is equal. When R=400Ω,the bridge is balanced. On inter-changing P and Q, the value of R, for balance, is405Ω.

The value of X is close to :

ans:

Initiality

Q

P

=

X

R

1

____(1)

After interchanging P and Q

P

Q

=

X

R

2

_____(2)

From (1) and (2)

1=

X

2

R

1

×R

2

X=

R

1

R

2

X=

400×405

=402.5Ω