Question

A voltmeter of range $3V$ and resistance $200\Omega$ cannot be converted to an ammeter of range

• A. $10mA$
• B. $100mA$
• C. $1A$
• D. $10A$

Answer 1

The correct option is A $10mA$

A voltmeter can be converted into ammeter by changing the calibration scales of the voltmeter. For the given voltmeter, maximum current is given by $I=V/R=3/200A=15mA$

Range of ammeter can be increased by adding a shunt to the original ammeter. It cannot however be reduced. So, we cannot get an ammeter of range $10mA$ with the given voltmeter.