In the following circuit, a voltmeter V is connected across a lamp L . What change would occur in voltmeter reading if the resistance R is reduced

Step-by-step solution

Here, the emitter-base junction of the N-P-N transistor is forward biased with battery V B B through resistance R . When the value of R is reduced, then the base current i b will increase. As a result, the collector current will also increase. ( i c = β i b ) . Due to the increase in i c , the potential difference across L increases and hence the reading of voltmeter will increase.