More Classes
5th Class
6th Class
7th Class
8th Class
9th Class
10th Class
11th Class
12th Class
NAT I
NAT II
CSS
IQ
General Knowledge
MDCAT
ECAT
GAT General
GAT Subject
Other Links
Go to Home
Online Tests
ECAT Pre General Science Physics Chapter 16 Alternating Current Online Test MCQs With Answers
Question # 1
Due to the high value of the input resistance, practically, the value of the current which flows between the input terminals is
Choose an answer
zero
small
large
very large
Previous
Skip
Next
Question # 2
At resonance frequency the impedance of parallel resonance circuit is
Choose an answer
Maximum
Minimum
Zero
None of the above
Previous
Skip
Next
Question # 3
At resonance, the phase angle for RLC series resonance circuit equals
Choose an answer
0
°
90
°
180
°
270
°
Previous
Skip
Next
Question # 4
The basic circuit element in D.C. circuit is:
Choose an answer
A capacitor
A resistor
An inductor
Both (A) and (C)
Both (A) and (B)
Previous
Skip
Next
Question # 5
Nowadays, Most of the electric energy is produced by the A.C. generators using:
Choose an answer
Hydal water
Geothermal energy
Solar energy
Biomass
Both (B) and (D)
Previous
Skip
Next
Question # 6
Which of the following diode is used for the detection of light
Choose an answer
photo diode
light emitting diode
photo voltaic cell
all of them
Previous
Skip
Next
Question # 7
The total reactance of a series RLC circuit at resonance is
Choose an answer
zero
Equal to the resistance
Infinity
Capacitive
Previous
Skip
Next
Question # 8
Alternating current can induce voltage because it has a
Choose an answer
High peak value
Varying magnetic field
Stronger field than direct curren
Constant magnetic field
Previous
Skip
Next
Question # 9
If 250V is the RMS value of alternative voltage, then its peak value V
o
will be:
Choose an answer
353.5V
250V
175V
zero
400V
Previous
Skip
Next
Question # 10
The magnitude of alternative voltage V:
Choose an answer
Always increase
Always decrease
Remains constant
Does not remain constant
None of these
Previous
Skip
Next
Question # 11
The device which allows only the flow of an A.C. through a circuit is
Choose an answer
Capacitor
Inductor
D.C. motor
Battery
Previous
Skip
Next
Question # 12
If the value of C in a series RLC circuit is increased, the resonant frequency
Choose an answer
Is not affected
Increase
Remains the same
Decreases
Previous
Skip
Next
Question # 13
When the pn-junction is forward biased. the current flows through it is of the order of
Choose an answer
mili-amperes
amperes
nano-amperes
micro-amperes
Previous
Skip
Next
Question # 14
The value of the potential difference across the depletion region for the case of germanium is
Choose an answer
0.3 V
0.5 V
0.7 V
0.9 V
Previous
Skip
Next
Question # 15
When the emitter-base junction of a transistor is reverse biased, collector current
Choose an answer
Reverses
Increases
Decreases
Stops
Previous
Skip
Next
Question # 16
For the normal operation of the transistor, its
Choose an answer
emitter-base and collector base junctions are forward biased
emitter-base junction is reversed biased and collector base junction is forward biased
emitter-base junction is forward biased and collector-base junction is reverse biased
any one of these
Previous
Skip
Next
Question # 17
Alternating current is produced by a voltage source which polarity:
Choose an answer
Remains the same
Reverse after period T
Keeps on reversing with time
Reverse after every time interval T/2
Both (C) and (D)
Previous
Skip
Next
Question # 18
In a normally biased n-p-n transistor, an electron c current I
E
flows from the
Choose an answer
emitter into the base
collector into the base
base into collector
none of these
Previous
Skip
Next
Question # 19
An A.C. voltmeter read 250 volts. The frequency of alternating is 50 Hz, the peak value of voltage is
Choose an answer
3525.0 volts
35.35 volts
353.5 volts
3.535 volts
Previous
Skip
Next
Question # 20
In free space, the speed of electromagnetic waves is
Choose an answer
3 x 10
8
ms
-1
3 x 10
6
ms
-1
4 x 10
7
ms
-1
3 x 10
9
ms
-1
Previous
Skip
Next
Question # 21
The waveform of alternating voltage is a:
Choose an answer
Square
Rectangular
Saw-tooth
Sinusoidal
None of these
Previous
Skip
Next
Question # 22
An A.C varies as a function of
Choose an answer
Current
Voltage
Time
Charge
Previous
Skip
Next
Question # 23
The closed loop gain of the inverting amplifier is written as
Choose an answer
G = R
2
/R
1
G = 1 + R
2
/R
1
G = -R
2
/R
1
G = 1 - R
2
/R
1
Previous
Skip
Next
Question # 24
The emitter-base junction of a transistor is forward-biased and collector-base junction is reverse-biased. If the base current is increased, its
Choose an answer
I
c
will decrease
V
CE
will increase
I
C
will increase
V
CC
will increase
Previous
Skip
Next
Question # 25
The impedance of RLC series resonance circuit at resonant frequency is
Choose an answer
Greater than R
Equal to R
Less than R
None of these
Previous
Skip
Next
Question # 26
The output voltage of half wave rectification is in the form of
Choose an answer
a smooth curve
a smooth wave
pulses
all of the above
Previous
Skip
Next
Question # 27
If we connected the ordinary DC ammeter to measure alternating current, it would measure its:
Choose an answer
Instantaneous value
RMS value
Value averaged over a cycle
Either (B) or (C)
Either (A) or (C)
Previous
Skip
Next
Question # 28
In a transistor, if the central region is n-type, then this type of transistor is known as
Choose an answer
n-p-n transistor
p-n-p transistor
either of these
none of these
Previous
Skip
Next
Question # 29
In RLC series circuit, resonance occurs when
Choose an answer
X
L > Xc
X
L < Xc
X
L = Xc
None of these
Previous
Skip
Next
Question # 30
The R
1
= infinity and R
2
= 0, then the gain of non-inverting amplifier is
Choose an answer
zero
infinity
one
any one of these
Previous
Skip
Next
Back