An ammeter A reads \[\text{2 A}\] and the voltmeter \[V\] reads\[\text{2}0\text{ V}\]. The value of resistance R is (assuming finite resistaneces of ammeter and voltmeter)
A)exactly \[10\Omega \]
B) less than \[10\Omega \]
C)more than \[10\Omega \]
D) we cannot definitely say
Correct Answer:
B
Solution :
\[{{V}_{AB}}=(I-{{I}_{g}}).R={{I}_{g}}.G\] where, G = voltmeter resistance \[{{V}_{AB}}=20V\] \[I=2A\] and \[R=R\] \[20=(2-{{I}_{g}}).R\] \[R=\frac{20}{2-{{I}_{g}}}\] \[\therefore \] \[R<10\Omega \]