The specification for a silicon transistor are: ICQ = 300

The specification for a silicon transistor are: I_CQ = 300 mA and f_T = 350 MHz, h_fe = 150, C_ob = 4 pF. The values of r_b′e and g_m of the transistor will be—

1. 92 ohms, 75 mhos
2. 40 ohms, 118 mhos
3. 12·5 ohms, 12 mhos
4. 112 ohms, 10– 2 mhos

Given, I_ca = 300 mA, f_T = 350 MHZ, h_fe = 150, C_ob = 4pF

We know that, g_b’e =	g_m
	h_fe

then r_b’e =		1	=	h_fe	=	h_fe	=	h_fe·V_T
		g_b’e		g_m		I_CQ / V_T		I_CQ

or r_b’e	150 × 25 mV	= 12·5 Ω
	300 mA

or r_b’e = 12·5 ohms

and g_m=		I_C	=	300 mA	= 12 mhos
		V_T		25 mV