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

Question # 1

In a transistor, the central region is called

collector A
emitter B
base C
none of them D

Question # 2

Most OP-AMP operates with

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

Question # 3

SI unit of impedance is

hertz A
henry B
ampere C
ohms D

Question # 4

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 # 5

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 # 6

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 # 7

For a n-p-n transistor, the conventional current equation can be written as

I_E+ I_C= I_B A
I_C- I_B= I_E B
I_C+ I_B= I_E C
I_B+ I_E= I_C D

Question # 8

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 # 9

Unless stated otherwise, when we speak of A.C. meter reading, we usualy mean:

Peak value A
RMS value B
Instantaneous value C
Peak-to-peak value D
Both (A) and (C0 E

Question # 10

The wave form of alternating voltage is the graph between:

Voltage across X-axis and time across y-axis A
Current and time B
Voltage along y-axis and time along x-axis C
Voltage and current D
Either (B) or (D) E

Question # 11

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 # 12

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 # 13

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 # 14

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 # 15

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 # 16

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 # 17

In half wave rectification

both halves of the input voltage is used A
only one half of the input voltage is used B
either of these C
none of these D

Question # 18

Conversion of alternating current into direct current is called

amplification A
rectification B
conduction C
polarization D

Question # 19

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 # 20

Mathematical manipulation of the two quantized states can be best carried if they are represented by

high - low A
yes - no B
on - off C
0 - 1 D

Question # 21

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 # 22

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 # 23

Due to the high value of the input resistance, practically, the value of the current which flows between the input terminals is

zero A
small B
large C
very large D

Question # 24

The impedance of RLC series resonance circuit at resonant frequency is

Greater than R A
Equal to R B
Less than R C
None of these D

Question # 25

Electromagnetic waves transmit energy equal to

1/2 mv² A
m_oc² B
hf/c C
hf D

Question # 26

A digital system deals with quantities or variables which have

only one state A
only two discrete states B
three discrete states C
four discrete states D

Question # 27

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 # 28

The total reactance of a series RLC circuit at resonance is

zero A
Equal to the resistance B
Infinity C
Capacitive D

Question # 29

Average value of A.C voltage during one cycle is

1 A
Zero B
Maximum C
Variable D

Question # 30

Alternating current can be transmitted:

To long distance A
At very high cost B
At very low cost C
Both (A) and (C) D
Both (A) and (B) E

Sr.#	Question	Answer
1	The most common source of alternating voltage is:	A. Motor B. Transformer C. AC genrator D. Both (A) and (C)
2	When the pn-junction is connected reversed biased, its resistance is of the order of	A. few ohms B. few kilo-ohms C. few mega-ohms D. few mili-ohms
3	The phase angle of a series RLC circuit at resonance is	A. 180° B. 90° C. 0° D. None of the these
4	In which of the following diodes when an electron combines with a hole during the forward biasing, photon of visible light is emitted.	A. photo diode B. light emitting diode C. photo voltaic cell D. all of them
5	Electromagnetic waves transmit energy equal to	A. 1/2 mv² B. m_oc² C. hf/c D. hf
6	SI unit of impedance is	A. hertz B. henry C. ampere D. ohms
7	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
8	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
9	In series RC circuit when R=X_c, then the phase angle is	A. 0° B. 90° C. 70° D. 45°
10	Peak value of alternative current is:	A. one of its Instantaneous value B. Equal to its RMS value C. The same as its peak-to-peak value D. Both (B) and (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