Practicing Success

Target Exam

CUET

Subject

Physics

Chapter

Semiconductors and Electronic Devices

Question:

While a collector to emitter voltage is constant in a transistor, the collector current changes by 8.2 mA when the emitter current changes by 8.3 mA. The value of forward current ratio is:

Options:

82

83

8.2

8.3

Correct Answer:

82

Explanation:

Here, $ΔE_E=8.3mA, ΔI_C= 8.2mA$

As $ΔI_E =ΔI_B+ΔI_C$

$∴ΔI_B = ΔI_E −ΔI_C = 8.3 mA – 8.2 mA = 0.1 mA$

Forward current ratio, $h_{fe}=[\frac{ΔI_C}{ΔI_B}]_{V_{CE\,is\,constant}}=[\frac{8.2mA}{0.1mA}]=82$