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

Options

A. Increases
B. Decreases
C. Remains same
D. None of these

Answer

A

Explanation

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