Question

The diagram shows a CE circuit using a silicon transistor. Calculate the 

(a) base current 

(b) collector current. 

[V_BB = 2V, V_CC = 10V, 

R_B = 100 kΩ, 

R_L = 1 kΩ, [β_dc = 200]

Answer 1

Data : V_BB = 2 V, 

V_CC = 10 V, 

R_B = 100 kΩ, 

R_L = 1 kΩ,

β_dc = 200.

Since it is a silicon transistor, the emitter-base barrier potential, V = 0.7 V.

The voltage across the base resistor is

V_BB – V_BE = 2 – 0.7 = 1.3 V

Therefore, the base current,

I_B =  \(\cfrac{V_{BB}−V_{BE}}{R_B}\) = \(\cfrac{1.3}{10^5}\) = 1.3 x 10^-5 = 13 μA

The collector current,

I_C = βI_B = 200 × 1.3 × 10^-5 = 2.6 × 10^-3 A = 2.6mA