ECAT Pre General Science Chapter 16 online mcq test with answers for Physics chapter 16 (Alternating Current)

Question # 1

In a normally biased n-p-n transistor, an electron c current I_Eflows from the

emitter into the base A
collector into the base B
base into collector C
none of these D

Question # 2

Which of the following diode is used for the detection of light

photo diode A
light emitting diode B
photo voltaic cell C
all of them D

Question # 3

The circuit which is used to smooth the output voltage of the full-wave rectification is known as

transformer A
rectifier B
filter C
none of these D

Question # 4

Peak value of alternative current is:

one of its Instantaneous value A
Equal to its RMS value B
The same as its peak-to-peak value C
Both (B) and (C) D
None of these E

Question # 5

A resonance curve for RLC series circuit is a plot of frequency versus

Voltage A
Current B
Impedance C
Reactance D

Question # 6

When the emitter-base junction of a transistor is reverse biased, collector current

Reverses A
Increases B
Decreases C
Stops D

Question # 7

At resonance frequency the impedance of parallel resonance circuit is

Maximum A
Minimum B
Zero C
None of the above D

Question # 8

The value of the potential difference across the depletion region for the case of germanium is

0.3 V A
0.5 V B
0.7 V C
0.9 V D

Question # 9

Transmitting antenna emits

Magnetic waves A
Electric waves B
Electromagnetic waves C
Sound waves D

Question # 10

OP-AMP has the following input terminals

one A
two B
three C
four D

Question # 11

If the value of C in a series RLC circuit is increased, the resonant frequency

Is not affected A
Increase B
Remains the same C
Decreases D

Question # 12

When the pn-junction is connected reversed biased, its resistance is of the order of

few ohms A
few kilo-ohms B
few mega-ohms C
few mili-ohms D

Question # 13

A P-N juction or semiconductor diode cannot be used as

A rectifier A
Detector B
Oscillator C
An amplifier D

Question # 14

The highest value reached by the voltage or current:

In quarter cycle is called Instantaneous value A
In half cycle is called peak-to-peak value B
In one cycle is called peak value C
In half cycle is called Instantaneous value D
None of these E

Question # 15

For the normal operation of the transistor, its

emitter-base and collector base junctions are forward biased A
emitter-base junction is reversed biased and collector base junction is forward biased B
emitter-base junction is forward biased and collector-base junction is reverse biased C
any one of these D

Question # 16

Conversion of alternating current into direct current is called

amplification A
rectification B
conduction C
polarization D

Question # 17

An A.C. voltage is applied across the inductor. When the frequency of the voltage is increased, the current

Decreases A
Increases B
Does not change C
Momentarily goes to zero D

Question # 18

When a transistor is used as a switch the circuit in which the current is to be switched OFF and ON, is connected between the

base and emitter A
collector and emitter B
base and collector C
any one of these D

Question # 19

In RLC series circuit, resonance occurs when

X_{L > Xc} A
X_{L < Xc} B
X_{L = Xc} C
None of these D

Question # 20

The output voltage of half wave rectification is in the form of

a smooth curve A
a smooth wave B
pulses C
all of the above D

Question # 21

The basic circuit elements of A.C circuit are

Resistor A
Inductor B
Capacitor C
All the three D

Question # 22

A sinusoidally alternating voltage or current can be graphically represented by a:

Vector A
Rotating vector B
Clockwise vector C
Anticlockwise voltage vector D
None of these E

Question # 23

The most common source of alternating voltage is:

Motor A
Transformer B
AC genrator C
Both (A) and (C) D
Both (A) and (B) E

Question # 24

Which of the following diodes can operate in the reverse biased condition

photo diode A
light emitting diode B
photo voltaic cell C
none of these D

Question # 25

A signal is amplified at the output without any change of phase, if it is applied at the

inverting input A
non-inverting input B
at any of the input C
none of these D

Question # 26

The phase angle of a series RLC circuit at resonance is

180° A
90° B
0° C
None of the these D

Question # 27

A diode characteristic curve is a plot between

current and time A
voltage and time B
voltage and current C
forward voltage and reversed voltage D

Question # 28

Nowadays, Most of the electric energy is produced by the A.C. generators using:

Hydal water A
Geothermal energy B
Solar energy C
Biomass D
Both (B) and (D) E

Question # 29

When either L or C is increased, the resonant frequency of the RLC series circuit

Increases A
Decreases B
Remains the same C
Becomes zero D

Question # 30

When electrons in the transmitting antenna vibrate 94000 time per second, they produce radiowaves having frequency

9.4 kHz A
940 kHz B
94 kHz C
None of these D

Sr.#	Question	Answer
1	The value of the input resistance of OP-AMP is of the order of	A. few ohms B. few hundred ohms C. several kilo ohms D. several maga ohms
2	The highest value reached by the voltage or current:	A. In quarter cycle is called Instantaneous value B. In half cycle is called peak-to-peak value C. In one cycle is called peak value D. In half cycle is called Instantaneous value
3	The basic circuit elements of A.C circuit are	A. Resistor B. Inductor C. Capacitor D. All the three
4	When the p-n junction is forward biased its resistance is of the order of	A. few mega ohms B. few kilo ohms C. few ohms D. few milli ohms
5	The basic circuit element in D.C. circuit is:	A. A capacitor B. A resistor C. An inductor D. Both (A) and (C)
6	Average value of A.C voltage during one cycle is	A. 1 B. Zero C. Maximum D. Variable
7	The magnitude of alternative voltage V:	A. Always increase B. Always decrease C. Remains constant D. Does not remain constant
8	The input resistance of the OP-AMP is the resistance between the	A. (-) input and output B. (+) input and output C. (-) and (+) inputs D. between any inputs
9	A signal appears after amplification, at the output terminal with a phase shift of 180° , if it is applied at	A. inverting input B. non-inverting input C. any one of the input terminal D. none of them
10	For a n-p-n transistor, the conventional current equation can be written as	A. I_E+ I_C= I_B B. I_C- I_B= I_E C. I_C+ I_B= I_E D. I_B+ I_E= I_C

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ECAT Pre General Science Physics Chapter 16 MCQ Test With Answer

MCQ's Test For ECAT Pre General Science Physics Chapter 16 Alternating Current

ECAT Pre General Science Physics Chapter 16 Alternating Current

In a normally biased n-p-n transistor, an electron c current IEflows from the