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

Question # 1

In which of the following components, pn-junction is used

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

Question # 2

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 # 3

Alternating current can induce voltage because it has a

High peak value A
Varying magnetic field B
Stronger field than direct curren C
Constant magnetic field D

Question # 4

In series RC circuit when R=X_c, then the phase angle is

0° A
90° B
70° C
45° D

Question # 5

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

A rectifier A
Detector B
Oscillator C
An amplifier D

Question # 6

Electromagnetic waves transmit energy equal to

1/2 mv² A
m_oc² B
hf/c C
hf D

Question # 7

Alternating current is produced by a voltage source which polarity:

Remains the same A
Reverse after period T B
Keeps on reversing with time C
Reverse after every time interval T/2 D
Both (C) and (D) E

Question # 8

Most OP-AMP operates with

+ 6 V supply A
+ 10 V supply B
+ 12 V supply C
+ 24 V supply D

Question # 9

The average of A.C. current and voltage over a complete cycle is

Maximum A
zero B
Neither zero nor maximum C
None of these D

Question # 10

The amplifier which us used to perform mathematical operations electronically is known as

calculator A
OP-AMP B
computer C
any one of them D

Question # 11

Which one of the following Electro-magnetic wave have the highest frequency and shortest wave-length

X-rays A
Ultraviolet rays B
y-rays C
Cosmic rays D

Question # 12

OP-AMP has the following input terminals

one A
two B
three C
four D

Question # 13

When the pn-junction is in reversed biased, current flows through the junction due to the

majority carriers A
minority carriers B
either of them C
none of them D

Question # 14

At resonance frequency the impedance of parallel resonance circuit is

Maximum A
Minimum B
Zero C
None of the above D

Question # 15

The phase angle of a series RLC circuit at resonance is

180° A
90° B
0° C
None of the these D

Question # 16

Which of the following diode is used to derive the current in external circuit when light is incident in the circuit

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

Question # 17

Chock consumes externally small

Charge A
Current B
Power C
Potential D

Question # 18

The Instantaneous value of alternative current maybe:

The same as its RMS value A
Greater than its Rms value B
The same as its peak value C
Any of these D
None of these E

Question # 19

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 # 20

The value of the input resistance of OP-AMP is of the order of

few ohms A
few hundred ohms B
several kilo ohms C
several maga ohms D

Question # 21

The value of current gain of n-p-n transistor is of the order of

tens A
hundreds B
thousands C
ten thousands D

Question # 22

The device which allows only the flow of an A.C. through a circuit is

Capacitor A
Inductor B
D.C. motor C
Battery D

Question # 23

A signal appears after amplification, at the output terminal with a phase shift of 180° , if it is applied at

inverting input A
non-inverting input B
any one of the input terminal C
none of them D

Question # 24

In describing functions of digital systems, a closed switch will be shown as

0 A
1 B
low C
any one of these D

Question # 25

In RLC series circuit, resonance occurs when

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

Question # 26

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 # 27

The r.m.s. value of alternating current is equal to its maximum value at angle of

60° A
45° B
30° C
90° D

Question # 28

The input resistance of the OP-AMP is the resistance between the

(-) input and output A
(+) input and output B
(-) and (+) inputs C
between any inputs D

Question # 29

To design a resonant circuit of frequency 100 KHz with an inductor of inductance 5 mH, we need a capacitor of capacitance

5.07 pF A
50 pF B
0.507 pF C
507 pF D

Question # 30

At resonance, the phase angle for RLC series resonance circuit equals

0° A
90° B
180° C
270° D

Sr.#	Question	Answer
1	The average of A.C. current and voltage over a complete cycle is	A. Maximum B. zero C. Neither zero nor maximum D. None of these
2	An A.C. voltmeter read 250 volts. The frequency of alternating is 50 Hz, the peak value of voltage is	A. 3525.0 volts B. 35.35 volts C. 353.5 volts D. 3.535 volts
3	The output voltage of half wave rectification is in the form of	A. a smooth curve B. a smooth wave C. pulses D. all of the above
4	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
5	The closed loop gain of the inverting amplifier is written as	A. G = R₂/R₁ B. G = 1 + R₂/R₁ C. G = -R₂/R₁ D. G = 1 - R₂/R₁
6	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
7	Which of the following diode is used for the detection of light	A. photo diode B. light emitting diode C. photo voltaic cell D. all of them
8	An A.C varies as a function of	A. Current B. Voltage C. Time D. Charge
9	Electromagnetic waves transmit energy equal to	A. 1/2 mv² B. m_oc² C. hf/c D. hf
10	The length of rotating vector (on a certain scale) represents the:	A. Peak value of alternating quantity B. RMS value of alternating quantity C. Instantaneous value of alternating quantity D. Either (B) or (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