Question

A student connects a voltmeter, ammeter and resistance according to the circuit given, If the voltmeter reading is 20 V and ammeter reading is 4 A, then the resistance will be :-

• A. equal to $5\Omega$
• B. more than $5\Omega$
• C. less than $5\Omega$
• D. equal to $10\Omega$

Answer 1

The correct option is B more than $5\Omega$

If voltmeter is not ideal, current $x$ will flow through it and ($4-x$) current will flow through $R$.
Thus, $R=\frac{20}{4-x}>5$
current is further reduced due the ammeter connected in series.