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

Question # 1

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 # 2

Average value of A.C voltage during one cycle is

1 A
Zero B
Maximum C
Variable D

Question # 3

The alternative voltage of current is actually measured by:

Its RMS value A
Square root of its mean square value B
Instantaneous value C
Peak value D
Both (A) and (B) E

Question # 4

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 # 5

In n-p-n transistor, emitter base junction is kept

reversed A
forward biased B
may be reversed or may be forward biased C
none of these D

Question # 6

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

Question # 7

The closed loop gain of the inverting amplifier is written as

G = R₂/R₁ A
G = 1 + R₂/R₁ B
G = -R₂/R₁ C
G = 1 - R₂/R₁ 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

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

A rectifier A
Detector B
Oscillator C
An amplifier D

Question # 10

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 # 11

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 # 12

The emitter-base junction of a transistor is forward-biased and collector-base junction is reverse-biased. If the base current is increased, its

I_cwill decrease A
V_CEwill increase B
I_Cwill increase C
V_CCwill increase D

Question # 13

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 # 14

If 250V is the RMS value of alternative voltage, then its peak value V_owill be:

353.5V A
250V B
175V C
zero D
400V E

Question # 15

During the negative half-cycle of the half-wave rectification, the diode

does not conduct A
conducts B
either of these C
none of these D

Question # 16

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 # 17

Conversion of alternating current into direct current is called

amplification A
rectification B
conduction C
polarization D

Question # 18

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 # 19

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 # 20

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 # 21

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 # 22

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 # 23

The open loop gain of OP-AMP is of the order of

10² A
10³ B
10⁴ C
10⁵ D

Question # 24

If we connected the ordinary DC ammeter to measure alternating current, it would measure its:

Instantaneous value A
RMS value B
Value averaged over a cycle C
Either (B) or (C) D
Either (A) or (C) E

Question # 25

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 # 26

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 # 27

The value of output resistance of OP-AMOP is of the order of

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

Question # 28

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 # 29

A changing magnetic flux creates around itself

An electromotive force A
An electric field (changing electric flux) B
Magnetic field C
None of the above D

Question # 30

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

Sr.#	Question	Answer
1	A diode characteristic curve is a plot between	A. current and time B. voltage and time C. voltage and current D. forward voltage and reversed voltage
2	If we connect a A.C. volt meter to read A.C. voltage, It would read its:	A. RMS value B. Instantaneous value C. Valued average over a cycle D. Zero
3	The basic circuit element in D.C. circuit is:	A. A capacitor B. A resistor C. An inductor D. Both (A) and (C)
4	When the pn-junction is in reversed biased, current flows through the junction due to the	A. majority carriers B. minority carriers C. either of them D. none of them
5	Transmitting antenna emits	A. Magnetic waves B. Electric waves C. Electromagnetic waves D. Sound waves
6	Due to the high value of the input resistance, practically, the value of the current which flows between the input terminals is	A. zero B. small C. large D. very large
7	Which of the following diodes can operate in the reverse biased condition	A. photo diode B. light emitting diode C. photo voltaic cell D. none of these
8	The power factor of resonant series circuit is	A. 1 B. 0 C. -1 D. 0.5
9	In series RC circuit when R=X_c, then the phase angle is	A. 0° B. 90° C. 70° D. 45°
10	The value of output resistance of OP-AMOP is of the order of	A. few ohms B. few hundred ohms C. several kilo ohms D. several mega ohms

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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