When a current of 5mA is passed through a galvanometer having a coil of resistance `15Omega`, it shows full sacle deflection. The value of the resistance to be put in series with the galvanometer to convert it into a voltmeter of range `0-10V` is:

Options

A. `2.535 xx10^(3)Omega`
B. `4.005 xx10^(3)Omega`
C. `1.985 xx10^(3)Omega`
D. `2.045 xx10^(3)Omega`

Answer

C

Explanation

Given : Current through the galvanometer ,
`i_g =5xx10^(-3)A`
Galvanometer resistance , `G = 15 Omega`
Let resistance R to be put in series with the galvanometer to convert it into a voltmeter.
`V=i_(g)(R+G)`
`10=5xx10^(-3) (R+15)`
`:. R = 2000 - 15 = 1985 = 1.985 xx10^3Omega`