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

Question # 1

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 # 2

In an A.C circuit with resistor only, the current and voltage have a phase angle of

90° A
0° B
180° C
none of these D

Question # 3

In a transistor, if the central region is p-type then this type of transistor is known as

p-n-p transistor A
n-p-n transistor B
either of these C
none of these D

Question # 4

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

Reverses A
Increases B
Decreases C
Stops D

Question # 5

The magnitude of alternative voltage V:

Always increase A
Always decrease B
Remains constant C
Does not remain constant D
None of these E

Question # 6

At resonance frequency the impedance of parallel resonance circuit is

Maximum A
Minimum B
Zero C
None of the above D

Question # 7

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 # 8

The length of rotating vector (on a certain scale) represents the:

Peak value of alternating quantity A
RMS value of alternating quantity B
Instantaneous value of alternating quantity C
Either (B) or (C) D
Either (A) or (B) E

Question # 9

During the positive half-cycle in the half-wave rectification,the diode

does not conduct A
conducts B
either of these C
neither of these D

Question # 10

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 # 11

SI unit of impedance is

hertz A
henry B
ampere C
ohms D

Question # 12

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 # 13

At resonance, the impedance of RLC series circuit is

Maximum A
Zero B
Minimum C
Determinate D

Question # 14

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 # 15

The waveform of alternating voltage is a:

Square A
Rectangular B
Saw-tooth C
Sinusoidal D
None of these E

Question # 16

The total reactance of a series RLC circuit at resonance is

zero A
Equal to the resistance B
Infinity C
Capacitive D

Question # 17

During each cycle, alternating voltage reaches a peak value

One time A
Two times B
Four times C
A number of times depending on the frequency D

Question # 18

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 # 19

In a transistor, the central region is called

collector A
emitter B
base C
none of them D

Question # 20

Average value of A.C voltage during one cycle is

1 A
Zero B
Maximum C
Variable D

Question # 21

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 # 22

The sum of positive and negative peak values is called:

Instantaneous value A
Peak value B
Rms valuie C
Peak-to peak-value D
None of these E

Question # 23

A p-n junction is formed when a crystal of silicon is growth in such a way that its one half is doped with trivalent impurity and the other half with a impurity from

2nd group A
fourth group B
fifth group C
sixth group D

Question # 24

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

0° A
90° B
70° C
45° D

Question # 25

An A.C. voltmeter read 250 volts. The frequency of alternating is 50 Hz, the peak value of voltage is

3525.0 volts A
35.35 volts B
353.5 volts C
3.535 volts D

Question # 26

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 # 27

Chock consumes externally small

Charge A
Current B
Power C
Potential D

Question # 28

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 # 29

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

Voltage A
Current B
Impedance C
Reactance D

Question # 30

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

0 A
1 B
low C
any one of these D

Sr.#	Question	Answer
1	The RMS value of alternating current is:	A. 0.7 times at the peak value B. 0.5 times the peak value C. 0.7 times the Instantaneous value D. Equal to maximum voltage
2	In series RC circuit when R=X_c, then the phase angle is	A. 0° B. 90° C. 70° D. 45°
3	Which one of the following is correct?	A. V_o= 1.414 V_rms B. I_ams= 1.414 I_o C. VO = 10.70 Vrms D. Both a and b
4	OP-AMP has the following input terminals	A. one B. two C. three D. four
5	When the emitter-base junction of a transistor is reverse biased, collector current	A. Reverses B. Increases C. Decreases D. Stops
6	In a transistor, if the central region is p-type then this type of transistor is known as	A. p-n-p transistor B. n-p-n transistor C. either of these D. none of these
7	In describing functions of digital systems, a closed switch will be shown as	A. 0 B. 1 C. low D. any one of these
8	A digital system deals with quantities or variables which have	A. only one state B. only two discrete states C. three discrete states D. four discrete states
9	Average value of A.C voltage during one cycle is	A. 1 B. Zero C. Maximum D. Variable
10	In a normally biased n-p-n transistor, an electron c current I_Eflows from the	A. emitter into the base B. collector into the base C. base into collector D. none of these

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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