Question

For the given transistor circuit $V_{BE}$ = $0.7\mathrm{V}$. Find I,

• A. $3.7mA$
• B. $2.2mA$
• C. $1.8mA$
• D. $1.5mA$

Answer 1

The correct option is A

$3.7mA$

Step 1: Given data

$V_{BE}=0.7V$

Step 2: Formula used

According to Ohm's law, the amount of current is proportional to the voltage applied to the circuit and inversely proportional to the resistance of the circuit.

$I=\frac{V}{R}[whereV=voltage,I=current,R=resis\tan ce]$

Step 3: Calculating current $I$

We can find the base current in the above transistor circuit by applying KVL in the first loop.

Here, resistance, $R=2k\Omega =2\times {10}^3[As,1K\Omega =1000\Omega ]$

$$\begin{gathered} V=5-V_{BE} \\ V=5-0.7 \\ V=4.3 \end{gathered}$$

Applying formula,

$$\begin{gathered} I=\frac{V}{R} \\ I=\frac{4.3}{2\times {10}^3} \\ I=3.7mA \end{gathered}$$

Hence, the value of I is $3.7mA$.