Why is potentiometer preferred over a voltmeter for measuring emf? or explain. Potentiometer acts as an ideal voltmeter .

An ideal voltmeter has

The resistance of an ideal voltmeter is

Distinguish between potentiometer and voltmeter..

Potentiometer is better for measuring the potential difference than the voltmeter because

State the advantages of potentiometer over voltmeter.

A potentiometer is an ideal instrument for measuring potential difference or e.m.f. because

Ammeter : ….. : : Voltmeter : to measure the P.D.

What does an ammeter or voltmeter measure? Average value or peak value.

Give reasons : Why is mercury preferred over water in making thermometers even though both of them have similar coefficient of volume expansion ?

State the disadvantages of potentiometer over voltmeter.