The base-biased transistor circuit of figure is subjected

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The base-biased transistor circuit of figure is subjected to increase in junction temperature from 25°C to 75°. If β increases from 100 to 150 with rising temperature, percentage change in a-point value (I_C, V_CE) over the temperature range will be (assume V_BE reacts at 0.7 V)

1. – 40%
2. – 44.57%
3. – 46.57%
4. – 48.0%

Correct Option: B

I_B =	V_CC - V_BE	=	12 - 0.7	= 0.113 mA
	R_B		100 × 10³

I_C = β I_B = 100 × 0.113 = 11.3 mA
V_CE = V_CC - I_C R_C
= 12 – (11.3 × 10^–3 × 500) = 5.35 V
At 75° C I_B = 0.113 mA
I_C = β I_B = 150 × 0.113 = 16.95 mA
V_CE = 12 – (16.95 × 10^–3 × 500) = 3.32 V

∴ ∆I_C =	16.75 - 1.3	× 100 = 50% (increased)
	11.3

and ∆ V_CE =	3.52 - 6.35	× 100 = -44.57% (decreased)
	11.3