A student connects an ammeter A and a voltmeter V to measures a resistance R as shown in figure. If the voltmeter reads 20 V and the ammeter reads 4A, then the value of R is :- (voltmeter and ammeter are not ideal)

Question

A student connects an ammeter A and a voltmeter V to measures a resistance R as shown in figure. If the voltmeter reads 20 V and the ammeter reads 4A, then the value of R is :- (voltmeter and ammeter are not ideal) <img class="img-fluid question-image" alt="Question" src="https://cdn.tardigrade.in/q/nta/p-cok4binquhm5maiz.jpg" /> (A) Equal to 5 Ω (B) Greater than 5 Ω (C) Less than 5 Ω (D) Greater or less than 5 Ω depending upon the direction of current

Tardigrade Admin · Accepted Answer

As the given ammeter and voltmeter are not considered ideal, we use 4(R + RA)=20 R=5-RA;RA arrow Resistance of ammeter

Q. A student connects an ammeter $A$ and a voltmeter $V$ to measures a resistance $R$ as shown in figure. If the voltmeter reads $20 V$ and the ammeter reads $4 A,$ then the value of $R$ is :- (voltmeter and ammeter are not ideal)

Equal to $5 Ω$

Greater than $5 Ω$

Less than $5 Ω$

Greater or less than $5 Ω$ depending upon the
direction of current

As the given ammeter and voltmeter are not considered ideal, we use
$4 (R + R_{A}) = 20$
$R = 5 - R_{A}; R_{A} \to$ Resistance of ammeter

Q. A student connects an ammeter A and a voltmeter V to measures a resistance R as shown in figure. If the voltmeter reads 20V and the ammeter reads 4A, then the value of R is :- (voltmeter and ammeter are not ideal)

Equal to 5Ω

Greater than 5Ω

Less than 5Ω

Greater or less than 5Ω depending upon the direction of current