The out put characteristics of a transistor is shown in the figure. When $\mathrm{V}_{\mathrm{CE}}$ is 10 V and $\mathrm{I}_{\mathrm{C}}=4.0$ mA, then value of $\beta_{\mathrm{ac}}$ is ____.

JEE Main · 2020 · 06 Sep 2020 · Shift 2 · Semiconductors

The out put characteristics of a transistor is shown in the figure. When

V_{CE}

is 10 V and

I_{C} = 4.0

mA, then value of

β_{ac}

is ____.

Answer: 150

The ac current gain is

β_{a c} = \frac{Δ I _{C}}{Δ I _{B}}

, read along the fixed line

V_{C E} = 10 V

on the output characteristics. Stepping between the characteristic curves there, the base current changes from

20 μ A

30 μ A

while the collector current changes from

3.0 mA

4.5 mA

. Hence

β_{a c} = \frac{1.5 \times 1 0 ^{- 3}}{10 \times 1 0 ^{- 6}} = 150

JEE Main · 2020 · 06 Sep 2020 · Shift 2 · Integer answer