Your cart is empty.
Practice each question, then open the answer or worked solution.
In the circuit shown in the figure, when the input voltage of the base resistance is 10V, Vbe is zero and Vce is also zero. Find the values of Ib, Ic and β.
Vi = 10 V
Rb = 400 kilo ohms
Vbe = 0
Vce = 0
Rc = 3 kilo ohms
Ib = 25 micro ampere
Rc = 10 V
Ic = 3.33 mA
Current gain = 133
Draw the output signals C1 and C2 in the given combination of gates in the figure.
14.34 Consider the circuit arrangement in which the input and output characteristics of NPN transistor in CE configuration
Select the values of RB and RC for a transistor whose VBE = 0.7 V, so that the transistor is operating at point Q as shown in the characteristics shown in the figure (b). Given that the input impedance of the transistor is very small and VCC = VBB = 16 V, also find the voltage gain and power gain of circuit making appropriate assumptions.
Vbe = 0.7V
Vcc = Vbb = 16V
Vce = 8V
Ic = 4 mA = 4 × 10-3 A
Ib = 30 × 10-6 A
Rc = 2 kilo ohms
Rb = 510 kilo ohms
Current gain = 1333
Voltage gain = 0.52
Power gain = 69
Assuming the ideal diode. Explain the waveform.
The waveform of the above circuit would be a sine wave with a dip off in the input wave.
Suppose a ‘n’-type wafer is created by doping Si crystal having 5 × 1028 atoms/m3 with 1ppm concentration of As. On the surface 200 ppm Boron is added to create the ‘P’ region in this wafer. Considering ni = 1.5 × 1016 m–3,
(i) Calculate the densities of the charge carriers in the n & p regions.
(ii) Comment which charge carriers would contribute largely for the reverse saturation current when the diode is reverse biased.
i) Ne = 5 × 1022 m3
Nh = 0.45 × 1010 m3
Nh = Na = 1 × 1025 m3
Ne = 2.25 × 107 m3
ii) The minority carrier holes of n-region would contribute largely for the reverse saturation current when the diode is reverse biased.
An X-OR gate has the following truth table:
| A | B | Y |
| 0 | 0 | 0 |
| 0 | 1 | 1 |
| 1 | 0 | 1 |
| 1 | 1 | 0 |
It is represented by the following logic relation
Build this gate using AND, OR, and NOT gates.
The logic relation is y = A.B + A.B
Consider a box with three terminals on top of it:
Three components namely, two germanium diodes and one resistor are connected across these three terminals in some arrangement. A student performs an experiment in which any two of these three terminals are connected in the circuit shown in the figure (b).
The student obtains graphs of current-voltage characteristics for an unknown combination of components between the two terminals connected in the circuit.
The graphs are
(v) When A is positive and C is negative
(vi) When A is negative and C is positive
From these graphs of current-voltage characteristic shown in the figures, determine the arrangement of components between A, B and C.
a) A is connected to the n-side of the PN junction and B is connected to the top-side of pn junction.
b) 0.7 V is the knee voltage.
c) Pn junction is connected to C and n-side of pn junction to B and knee voltage is 0.7 V.
d) The above conditions explains the connection of pn-junction along I and II with the resistance.
For the transistor circuit shown in Fig.14.19, evaluate VE, RB, RE given IC = 1 mA, VCE = 3V, VBE = 0.5 V and VCC = 12 V, β = 100.
Ic = Ie
Rc = 7.8 kilo ohm
Ic (Rc + Re) + Vce = 12
Ve = 1.2 V
Vb = Ve + Vbe = 1.7 V
I = 0.085 mA
Rb = 108 kilo ohms
In the circuit, find the value of RC.
Ie = Ic + Ib
IcRc + Vce + IeRe = Vcc
Rib + Vbe + IeRe = Vcc
Ib = 11.5/200 mA
Rc + Re = 1.56 kilo ohm
Rc = 560 Ohm
Semiconductor electronics refers to the different electronic circuits, components and devices that are made with a different kind of material, unlike metals and non-metals. Materials based on resistivity and conductivity are categorised into metals, non-metals and semiconductors. They have a wide range of applications, especially in the field of conducting and resisting electricity. Other topics discussed in this chapter are