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

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 (A) 82 (B) 83 (C) 8.2 (D) 8.3

Tardigrade Admin · Accepted Answer

Here, ÎIE = 8.3 mA ÎIC = 8.2 mA As ÎIE = ÎIB + ÎIC ∴ ÎIB = ÎIE - ÎIC = 8.3 mA - 8.2 mA = 0.1 mA Forward current ratio, hfe = [(ÎIC/ÎIB)]VCE is constant = [(8.2 mA/0.1 mA)] = 82

Q. 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

82

83

8.2

8.3

Here, $Δ I_{E} = 8.3 m A$
$Δ I_{C} = 8.2 m A$
As $Δ I_{E} = Δ I_{B} + Δ I_{C}$
$∴ Δ I_{B} = Δ I_{E} - Δ I_{C} = 8.3 m A - 8.2 m A = 0.1 m A$
Forward current ratio, $h_{f e} = [\frac{Δ I _{C}}{Δ I _{B}}]_{V_{CE} i s co n s t an t}$
$= [\frac{8.2 m A}{0.1 m A}] = 82$

Q. 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

82

83

8.2

8.3

Here, ΔIE​=8.3mA ΔIC​=8.2mA As ΔIE​=ΔIB​+ΔIC​ ∴ΔIB​=ΔIE​−ΔIC​=8.3mA−8.2mA=0.1mA Forward current ratio, hfe​=[ΔIB​ΔIC​​]VCE​isconstant​ =[0.1mA8.2mA​]=82

Here, $Δ I_{E} = 8.3 m A$
$Δ I_{C} = 8.2 m A$
As $Δ I_{E} = Δ I_{B} + Δ I_{C}$
$∴ Δ I_{B} = Δ I_{E} - Δ I_{C} = 8.3 m A - 8.2 m A = 0.1 m A$
Forward current ratio, $h_{f e} = [\frac{Δ I _{C}}{Δ I _{B}}]_{V_{CE} i s co n s t an t}$
$= [\frac{8.2 m A}{0.1 m A}] = 82$