NIELIT Technical Assistant_2016_march
Question 1 |
The thermionic emission current is given by
maxwell’s equation | |
Fermi-Dirac distribution | |
Langmuir child law | |
Richardson Dushman equation |
Question 2 |
Zener breakdown occurs
due to rupture of covalent bonds | |
due to thermally generated minority carriers | |
in lightly doped junctions | |
only in germanium diodes |
Question 3 |
Negative feedback in an amplifier
increase noise | |
reduce bandwidth | |
reduce gain | |
increase distortion |
Question 4 |
The gain of a bipolar transistor drops at high frequencies because of
early effect | |
parasitic inductive elements | |
high current in base | |
transistor capacitance |
Question 5 |
The main application of enhancement mode MOSFET is in
oscillator circuits | |
amplifier circuits | |
clipper circuit | |
switching circuits |
Question 6 |
Transducer is a device which
amplifies a given electrical signal | |
transfer an electrical signal from one place to another | |
translates a physical parameter into suitable electrical quantity | |
changes the waveform of an electrical signal |
Question 7 |
The turn ratio of a transformer is 20:1. If a load of 40 ohm is connected across the secondary. What will be the effective resistance seen looking into the primary ?
800 ohm | |
4 k ohm | |
8 k ohm | |
16 k ohm |
Question 8 |
N-channel FETs are considered better than p-channel FETs because
they consume less power | |
they have high switching time | |
mobility of electrons is greater than that of holes | |
they consume less power |
Question 9 |
In a 4-bit weighted resistor D/A converter, resistor value corresponding to LSB is 16 k ohm. The resistor value corresponding to MSB is
32 k ohm | |
15 k ohm | |
64 k ohm | |
2 k ohm |
Question 10 |
In a digital circuit, the clock is a
Flip-clop | |
Inverter | |
Monostable multivibrator | |
Free running multivibrator |
Question 11 |
In which of the following codes the successive numbers differ in only one bit position ?
ASCII | |
Gray Code | |
Excess-3 Code | |
BCD |
Question 12 |
An instruction used to set the carry flag in a computer can be classified as
data transfer | |
arithmetic | |
logical | |
program control |
Question 13 |
In FM modulation pre-emphasis is done for
low frequency components | |
high frequency components | |
middle frequency components | |
all frequency components |
Question 14 |
When modulation index of AM wave is increased from 0.5 to 1, the transmitted power
increases by 25% | |
increases by 33.3% | |
increases by 50% | |
remains same |
Question 15 |
The electric flux and field intensity inside a conducting sphere is
Minimum | |
Maximum | |
Uniform | |
Zero |
Question 16 |
A waveguide behaves as
high pass filter | |
low pass filter | |
band pass filter | |
all pass filter |
Question 17 |
In a lossless RLC circuit the transient current is
sinusoidal | |
square wave | |
triangular wave | |
non-oscillating |
Question 18 |
In an ac circuit, the maximum and minimum values of power factor can be
10 and 1 | |
1 and -1 | |
1 and 0 | |
Any positive value |
Question 19 |
In a circuit containing a complex impedance, maximum power transfer takes place when load is
pure resistance | |
equal to complex impedance | |
conjugate complex of the circuit impedance | |
inductive |
Question 20 |
The effect of doping intrinsic semiconductor is to
Move the Fermi level away from the centre of forbidden band | |
Move the Fermi level towards the centre of forbidden band | |
Change the crystal structure of the semiconductor | |
To keep the Fermi level at the middle of the forbidden band |
Question 21 |
Field Effect Transistor has
Large input impedance | |
Large output impedance | |
Large power gain | |
Small voltage gain |
There are 21 questions to complete.