41. A zener diode, having breakdown voltage equal to 15 V, is used in a voltage regulator circuit shown in figure. The current through the diode is ?
(a) 10 mA
(b) 15 mA
(c) 20 mA
(d) 5 mA
Answer : (d) 5 mA
\( \text{By parallel connection, } V_L = V_Z \)
\( i_L R_L = 15 \)
\( i_L \times 1000 = 15 \)
\( i_L = \frac{15}{1000}\,\text{A} \)
\( V_{in} = V_{R_s} + V_Z \)
\( 20 = i R_s + 15 \)
\( 5 = i R_s \)
\( 5 = (i_L + i_Z) R_s \)
\( 5 = (15\,\text{mA} + i_Z)\times 25 \)
\( \frac{5}{25} = 15\,\text{mA} + i_Z \)
\( 20\,\text{mA} = 15\,\text{mA} + i_Z \)
\( i_Z = 5\,\text{mA} \)
No comments:
Post a Comment
Please provide your valuable feedback. Students, Parents, Teachers.