mechanical effect of electric current

Asked by  | 9th Mar, 2008, 12:25: PM

Expert Answer:

First find the resistance of the galvanometer using the given information. R = V/I = 50mV/1mA= 50 ohms.

Then it is to be changed into an ammeter of range 0-0.5A. If shunt resistance is S then

igRg = (i-ig)S  potential drop across galvanometer equals potential drop across shunt.

where i is the maximum current equal to 0.5A
ig is the maximum current through the galvanometer which is 10mA

Rg is the resistance of the galvanometer which is 50 ohms

Then solve for S.

To change the galvanometer into a voltmeter of given range

use the equation

V = Ig(Rg+RS)

using the values find required series resistance, Rs.

Answered by  | 20th May, 2008, 01:03: PM

Queries asked on Sunday & after 7pm from Monday to Saturday will be answered after 12pm the next working day.