An ammeter is converted to a voltmeter by
An ammeter is converted to a voltmeter by
Right Answer is:
Putting a large resistance in series with the actual measuring part of the instrument
SOLUTION
An ammeter is used to measure current in amperes. It is a moving coil galvanometer in which a low resistance wire is connected in parallel. An ammeter is converted into a voltmeter by putting a large resistance in series with the actual measuring part of the instrument.
Let
Vr- Voltage range you required to measure (KNOWN VALUE)
If– Current required to full-scale deflection of your Ammeter (KNOWN VALUE)
Ra- Internal Resistance of Ammeter (Ideally Ra=0)
Rs- Resistance Should be Connected in Series with your existing Ammeter=?
Vr=(Ra + Rs) × (If)Vr=(Ra+Rs) × (If)
Vr=(Rs×If)Vr=(Rs×If) (We know that Ra=0 )
Rs=Vr/If