問題一覧
1
The main advantage of CMOS circuit is
low power consumption
2
If doubling the voltage across a resistor doubles the current through the resistor then
the resistor value did not change
3
A JFET is a ______.
is a voltage-controlled device
4
What can a semiconductor sense?
all of the above
5
What causes the depletion region?
diffusion
6
Assertion (A): In design of circuit using BJT, a derating factor is used. Reason (R): As the ambient temperature increases, heat dissipation becomes slower.
Both A and R are true and R is correct explanation of A
7
Assertion (A): Two transistors one n-p-n and the other p-n-p are identical in all respects (doping, construction, shape, size). The np-n transistor will have better frequency response. Reason (R): The electron mobility is higher than hole mobility.
Both A and R are true and R is correct explanation of A
8
Two ac sources feed a common variable resistive load as shown in figure. Under the maximum power transfer condition, what is the power absorbed by the load resistance RL?
625 W
9
In a class C power amplifier the input signal has a frequency of 250kHz. If the collector current pulses are 0.1 μs wide, the duty cycle of current waveform is
2.5%
10
Voltage drop is the:
difference in potential between 2 points
11
The concept on which Superposition theorem is based is.
Linearity
12
The primary function of the bias circuit is to
hold the circuit stable at the designed Q-point
13
What is the use of the compensation capacitor in op-amp?
Decreases the slew rate of op-amp
14
What is the power in the given circuit?
35 W
15
Which of the following oscillators is suitable for frequencies in the range of megahertz?
Hartley
16
When an input signal reduces the channel size, the process is called:
depletion
17
A current of 6 A flows for 10 minutes. What charge is transferred?
3600 C
18
Delta to wye or wye to delta transformation technique is applied to a ______ network.
three-terminal
19
Two capacitors of 1 μF and 2 μF capacitance are connected in parallel across a 30 V dc battery. After the capacitors have been charged, the charges across the two capacitors will be.
30 μC and 60 μC respectively
20
The magnetic field due to a current-carrying conductor takes form of:
concentric circles
21
If peak voltage on a bridge full wave rectifier circuit is 5V and diode cut-in voltage is 0.7, then peak inverse voltage on diode will be _________.
4.3V
22
If the reference point is changed to the earth point then any voltage taken w.r.t. the earth is known as
Absolute potential
23
A conductor is said to have resistance of one ohm if a potential difference of one volt across its terminals causes a current of X ampere to flow through it. What will be the value of X?
1
24
If voltage across a resistance doubles.
none of the above
25
An RLC series circuit is underdamped. To make it overdamped, the value of R
has to be increased
26
As temperature increases the number of free electrons and holes in an intrinsic semiconductor
increases
27
In an ideal op-amp, which is not true?
CMRR is zero
28
If the diameter of a wire is doubled, the current carrying capacity of the wire becomes
four times
29
A strong permanent magnet is plunged into a coil and left in the coil. What is the effect produced on the coil after a short time?
There is no effect
30
With 21 V applied, if R1 = 5 ohms, R2 = 35 ohms, and R3 = 14 ohms, what is the current of R2 if R1 is series connected with parallel circuit R2 and R3?
400 mA
31
For a base current of 10 μA, what is the value of collector current in common emitter if βdc = 100
1 mA
32
A straight conductor 500 mm long is moved with constant velocity at right angles both to its length and to a uniform magnetic field. Given that the e.m.f. induced in the conductor is 2.5 V and the velocity is 5 m/s, calculate the flux density of the magnetic field. If the conductor forms part of a closed circuit of total resistance 5 ohms, calculate the force on the conductor.
0.25N
33
From the given circuit below, we can conclude that.
transistor is faulty
34
If a resistance to which a constant voltage is applied is halved, what power dissipation will result?
Doubled
35
What is the total resistance?
3.2 k
36
Figure is a 24 Vr stabilized power supply. The zener is 24 V, 600 mW. The minimum zener current is 10 mA. Proper values R and maximum load current are
320 Ω, 15 mA
37
D-MOSFETs are sometimes used in series to construct a cascode highfrequency amplifier to overcome the loss of:
high input impedance
38
Ripple factor of bridge full wave rectifier is _________.
0.482
39
In figure, voltage across R2 = + 10 V. If VBE = 0.7 V and VE = 0.7 V and RE = 10 kΩ, current through RE is
0.93 mA
40
If the load in the given circuit is 120 k-ohms, what is the loaded output voltage?
15.79 V
41
In a parallel circuit, the individual branch currents are
inversely proportional to the branch resistance values
42
Calculate the resistivity of ntype semiconductor from the following data, Density of holes = 5 x 1012 cm-3. Density of electrons = 8 x 1013 cm-3, mobility of conduction electron = 2.3 x 104 cm2/ V-sec and mobility of holes = 100 cm2/V-sec
0.34 Ω-m
43
Intrinsic semiconductor material is characterized by a valence shell of how many electrons?
4
44
In a low pass filter as below, find the cut-off frequency for the following circuit.
636 Hz
45
When a material becomes a superconductor, its resistivity becomes
zero
46
A 25 Ω resistor has a voltage of 150 sin377 t. Find the corresponding power.
900 sin² 337 t
47
The drift velocity of electrons is
very small as compared to speed of light
48
What is the total resistance of a circuit when R1 (7 k ) is in series with a parallel combination of R2 (20 k ), R3 (36 k ), and R4 (45 k )?
17 k-ohms
49
The effect on an air gap in a magnetic circuit is to:
increase the reluctance
50
According to Kirchhoff’s voltage law, the algebraic sum of all IR drops and e.m.f. in any closed loop of a network is always.
Zero