At 0 K the forbidden energy gap in intrinsic semi conductor is about | |
A. | 10 eV [Wrong Answer] |
B. | 6 eV [Wrong Answer] |
C. | 1 eV [Correct Answer] |
D. | 0.2 eV [Wrong Answer] |
View Answer
Explanation:-
Answer : C Discuss it below : !! OOPS Login [Click here] is required to post your answer/result |
⇒ In figure the approximate voltage
base and emitter are - 8 V and - 7.3 V
base and collector are - 8 V and - 5 V
collector and emitter are - 5 V and - 7.3 V
base, emitter and collector are - 8, - 7.3 and - 5 V
⇒ If x = 0.1396 radians, the values of 1 - cos x and 2 sin^{2} (x / 2) using floating point arithmetic with a 4 digit mantissa are respectively
.1000 E - 1 each
.9727 E - 2 each
.1000 E - 1 and .9727 E - 2 respectively
.9727 E - 2 and .1000 E - 1 respectively
⇒ When a material is in superconducting state and a magnetic field is applied
the superconducting property is not affected
the superconducting property may be affected and resistivity may increase from zero to a low value
the superconducting property may be destroyed
the material may become an insulator
⇒
Assertion (A): In the circuit shown figure the diode is used to protect the active devices. Transistor T goes into saturation when a positive pulse is applied at base and non conducting
Reason (R): When the current in an inductor is suddenly stopped, a high voltage is induced across
Both A and R are correct and R is correct explanation for A
Both A and R are correct but R is not correct explanation for A
A is correct R is wrong
A is wrong R is correct
⇒ Reluctivity is analogous to
permeability
conductivity
resistivity
retentivity
⇒ When thyristors are connected in series and parallel, it may be necessary to have :
current derating
voltage derating
both current and voltage derating
none of the above
⇒ What is meant by "continuous collector current" in BJT?
Maximum collector current
Current at Quiescent condition
Leakage current
Junction Capacitance charging and discharging current
⇒ In a display specified as 600 x 400 the number of pixels across the display screen is
600
400
240000
either (a) or (b)
⇒ The resonance frequency is
ω_{r} = a
ω_{r} = b
ω_{r} = k
ω_{r} = ba
⇒ In the given figure the input is x(t) = A sin ωt. The steady state output y(tA sin (ωt + φ) where φ = tan^{-1} |G(jω)|
|G(jω)| A sin [ωt + ∠G(jω)]
|G(jω)| A sin [2ωt + ∠G(jω)]
A G(jω) sin [ωt + ∠G(jω)]
⇒ At absolute temperature
the forbidden energy gap in germanium is higher than that in silicon
the forbidden energy gap in germanium and silicon are equal
the forbidden energy gap in silicon is higher than that in germanium
none of the above
⇒ The fuse material used in electrical lines must have which one of the following properties?
High resistivity
Low conductivity
High melting point
Low melting point
⇒ A Darlington pair consist of
two CB amplifiers
two CC amplifiers
two cascaded CC amplifiers
two cascaded CE amplifiers
⇒ The accuracy of measurement using CRO is about
± 0.5%
± 0.05 %
± 1%
± 3%
⇒ For real and odd signals, the Fourier series coefficient a_{n} is
purely imaginary
purely real and even
purely imaginary and odd
purely real and odd
⇒ Consider the following about 'return' statement in C
- On executing the return statement, it immediately transfers the control back to the calling program.
- There is no restriction on the number of 'return' statements present in a function.
- The 'return' statement must be present at the end of called function.
All
1 and 2 only
1 and 3 only
2 and 3 only
⇒ For the K map in the given figure, the simplified expressio
x_{l} x_{2} x_{4} + x_{2} x_{4} + x_{1} x_{3}
x_{2} x_{4} + x_{2} x_{4} + x_{1} x_{3}
x_{1} x_{2} x_{4} + x_{l} x_{2} + x_{3} x_{4} + x_{2}x_{4}
x_{1} x_{2} + x_{2} x_{3} + x_{3}x_{4}
⇒ Rotation of a geosynchronous satellite means its
drift from stationary position
wobbling
three-axis stabilization
three-dimensional stabilization
⇒ The current in an RL series circuit is 1 - e^{-t} amperes. Then di/dt is
1 - e^{-t}
- e^{-t}
e^{t}
e^{-2t}
⇒ For a junction FET in the pinch off region as the drain voltage is increased, the drain current
becomes zero
abruptly decreases
abruptly increases
remains constant
⇒ In p mode of operation of magnetron the spikes due to phase focussing effect rotate at an angular velocity corresponding to
one pole/cycle
two pole/cycle
four pole/cycle
six pole/cycle
⇒ In the amplifier circuit of figure h_{fe} = 100 and h_{ie} = 1000 Ω. The voltage gain of amplifier is a
0.33
0.5
0.66
1
⇒ A generator is feeding power to a transmission line of characteristic impedance Z_{0}. The line is terminated in impedance Z_{L}. Standing waves will be set up if
Z_{L} = Z_{0}
Z_{L} < Z_{0}
Z_{L} > Z_{0}
both (b) and (c)
⇒ The logic realized by the circuit shown in figure belo
F = A - C
F = A + C
F = B ⊙ C
F = B ⊕ C
⇒ Which of the following describe the correct properties of an emitter follower circuit?
- It is a voltage series feedback circuit.
- It is a current series feedback circuit.
- Its voltage gain in less than unity.
- Its output impedance is very low.
1, 3 and 4
2, 3 and 4
2 and 3 only
2 and 4 only
⇒ A dielectric of relative permittivity ∈_{r} is subjected to a homogeneous electric field E. The dipole moment P per unit volume is given by
P = constant
P = ∈_{0} E
P = ∈_{0}(∈_{r} - 1) E
P = ∈_{r} E
⇒ The log magnitude plot of the given figure is
type 0 system
type 1 system
type 2 system
either type 0 or type 1 system
⇒ In the stabilized reactance modulators AFC system
the discriminator must have a fast time constant to prevent demodulation
the higher discriminator frequency the better the oscillator frequency stability
the discriminator frequency must not be too low, or the system will fail
phase modulation is converted into FM by the equalizer circuit
⇒ The h parameter h_{11} is the same in CE and CC circuit.
TRUE
FALSE
⇒ Which of these has lowest dielectric strength?
Dry air
Wet air
Cotton
Paper