In the given circuit diagram, a voltmeter 'V' is connected across a lamp 'L'. How would (i) the brightness of the lamp and (ii) voltmeter reading 'V' be affected, if the value of resistance 'R' is decreased ? Justify your answer.

Explanation

The given figure is Common Emitter (CE) configuration of an npn transistor . The input circuit is forward biased and collector circuit is circuit is reverse biased. As the base thus, increasing the base current `(I_(B))` and increasing the emitter current `(I_(E))`. This will increase the collector current `(I_(c)) " as " I_(E) = I_(B)+I_(C). " When " I_(c)` increases which flows through the lamp, the voltage across the bulb will also increase thus making the lamp brighter and as the voltage is connected in parallel with the lamp, the reading in the voltmeter will also increase.