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

Question # 1

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 # 2

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 # 3

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 # 4

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

0° A
90° B
180° C
270° D

Question # 5

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 # 6

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 # 7

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 # 8

The most common source of alternating voltage is:

Motor A
Transformer B
AC genrator C
Both (A) and (C) D
Both (A) and (B) E

Question # 9

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 # 10

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 # 11

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

Voltage A
Current B
Impedance C
Reactance D

Question # 12

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 # 13

The total reactance of a series RLC circuit at resonance is

zero A
Equal to the resistance B
Infinity C
Capacitive D

Question # 14

The power factor of resonant series circuit is

1 A
0 B
-1 C
0.5 D

Question # 15

An A.C varies as a function of

Current A
Voltage B
Time C
Charge D

Question # 16

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 # 17

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 # 18

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 # 19

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 # 20

Average value of A.C voltage during one cycle is

1 A
Zero B
Maximum C
Variable D

Question # 21

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 # 22

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 # 23

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 # 24

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 # 25

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 # 26

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 # 27

Most OP-AMP operates with

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

Question # 28

The basic circuit elements of A.C circuit are

Resistor A
Inductor B
Capacitor C
All the three D

Question # 29

The phase angle of a series RLC circuit at resonance is

180° A
90° B
0° C
None of the these D

Question # 30

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

Sr.#	Question	Answer
1	A resonance curve for RLC series circuit is a plot of frequency versus	A. Voltage B. Current C. Impedance D. Reactance
2	In which of the following components, pn-junction is used	A. light emitting diode B. photo diode C. photo voltaic cell D. all of these
3	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
4	Alternating current can induce voltage because it has a	A. High peak value B. Varying magnetic field C. Stronger field than direct curren D. Constant magnetic field
5	The basic circuit elements of A.C circuit are	A. Resistor B. Inductor C. Capacitor D. All the three
6	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
7	In an A.C circuit with resistor only, the current and voltage have a phase angle of	A. 90° B. 0° C. 180° D. none of these
8	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
9	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
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