The resistance of each arm of the wheat stone bridge is `10Omega`. A resistance of `10Omega` is connected in series with galvanometer then the equivalent resistance across the battery will be:-

Options

A. `10Omega`
B. `25Omega`
C. `45Omega`
D. `55Omega`

Answer

B

Explanation

Increase in velocity of James for each bullet fired `m_(b)Deltav_(b) = m_(j)Deltav_(J)`
`0.02 xx (500 - 40) = 100 Deltav_(J) " " [v_(b) = v_(bm) v_(J)]`
`Deltav_(J) = (92)/(1000)` (down the plane)
decreases in velocity of killing for each bullet fired `m_(b) v_(b) = m_(K) Deltav_(k)`
`0.02 xx 545 = deltav_(k) xx 100`
`Deltav_(k) = (109)/(1000)` (up the plane)
So decrease in relative velocity for each bullet fired.
`Deltav_(rel) = (92)/(1000) + (109)/(1000) = 0.2 m//s`
So to decrease relative velocity to zero.
No. of bullet fired `n = (1)/(0.5) xx 5 = 25`