question_answer

An ammeter and a voltmeter are joined in series to a cell. Their readings are A and V respectively. If a resistance is now joined in parallel with the voltmeter, then:

A)  A will decrease, V will increase

B)  A will increase, V will decrease

C)  both A and V will increase

D)  both A and V will increase

Correct Answer: B

Solution :

  When a resistance is joined in parallel with voltmeter. Now V and S are in parallel so it become an ammeter.   \[\therefore \]A and\[{{A}_{1}}\] the two ammeters are in series reading will become equal. \[\therefore \]A increases and in parallel R decreases which decreases V.