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

Question # 1

An A.C varies as a function of

Current A
Voltage B
Time C
Charge D

Question # 2

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 # 3

The waveform of alternating voltage is a:

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

Question # 4

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 # 5

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 # 6

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 # 7

The entire wave form of sinusoidal voltage is actually a set of all the:

Positive maximum value + V_oand negative maximum value -V_o A
Posiotive maximum value +V_oand zero B
Zero and negative maximum value -V_o C
Any of these D
None of these E

Question # 8

The closed loop gain of the non-inverting amplifier is given by

G = R₂/R₁ A
G = -R₂/R₁ B
G = 1 - R₂/R₁ C
G = 1 + T₂/R₁ D

Question # 9

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 # 10

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 # 11

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 # 12

The basic circuit element in D.C. circuit is:

A capacitor A
A resistor B
An inductor C
Both (A) and (C) D
Both (A) and (B) E

Question # 13

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 # 14

The R₁= infinity and R₂= 0, then the gain of non-inverting amplifier is

zero A
infinity B
one C
any one of these D

Question # 15

When the pn-junction is forward biased. the current flows through it is of the order of

mili-amperes A
amperes B
nano-amperes C
micro-amperes D

Question # 16

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

0° A
90° B
180° C
270° D

Question # 17

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 # 18

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 # 19

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 # 20

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 # 21

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 # 22

The phase at the positive peak of an A.C. cycle is:

0º
A
90º
B
180º
C
0 andᏘ D
Ꮨ/2 and 3Ꮨ/2 E

Question # 23

The basic circuit elements of A.C circuit are

Resistor A
Inductor B
Capacitor C
All the three D

Question # 24

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 # 25

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 # 26

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

A rectifier A
Detector B
Oscillator C
An amplifier D

Question # 27

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 # 28

Which one of the following is correct?

V_o= 1.414 V_rms A
I_ams= 1.414 I_o B
VO = 10.70 Vrms C
Both a and b D

Question # 29

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 # 30

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

Sr.#	Question	Answer
1	In series RC circuit when R=X_c, then the phase angle is	A. 0° B. 90° C. 70° D. 45°
2	Most OP-AMP operates with	A. + 6 V supply B. + 10 V supply C. + 12 V supply D. + 24 V supply
3	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
4	OP-AMP has the following input terminals	A. one B. two C. three D. four
5	The phase at the positive peak of an A.C. cycle is:	A. 0º B. 90º C. 180º D. 0 andᏘ
6	The time interval during which the Voltage source changes its polarity once is known as:	A. Time period T B. Half the time period C. Quarter the time period D. Two third of the time period
7	Unless stated otherwise, when we speak of A.C. meter reading, we usualy mean:	A. Peak value B. RMS value C. Instantaneous value D. Peak-to-peak value
8	The wave form of alternating voltage is the graph between:	A. Voltage across X-axis and time across y-axis B. Current and time C. Voltage along y-axis and time along x-axis D. Voltage and current
9	The most common source of alternating voltage is:	A. Motor B. Transformer C. AC genrator D. Both (A) and (C)
10	Conversion of alternating current into direct current is called	A. amplification B. rectification C. conduction D. polarization

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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