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

Question # 1

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

0° A
90° B
180° C
270° D

Question # 2

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 # 3

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 # 4

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

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

Question # 5

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

10² A
10³ B
10⁴ C
10⁵ D

Question # 6

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 # 7

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 # 8

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

Question # 9

In frequency modulation (FM), the carrier waves amplitude

Remains constant A
Increase B
Decreases C
None of these D

Question # 10

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 # 11

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 # 12

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 # 13

An A.C varies as a function of

Current A
Voltage B
Time C
Charge D

Question # 14

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 # 15

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 # 16

In a transistor, the central region is called

collector A
emitter B
base C
none of them D

Question # 17

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 # 18

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 # 19

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 # 20

The time interval during which the Voltage source changes its polarity once is known as:

Time period T A
Half the time period B
Quarter the time period C
Two third of the time period D
None of these E

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

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 # 23

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 # 24

The highest value reached by the voltage or current:

In quarter cycle is called Instantaneous value A
In half cycle is called peak-to-peak value B
In one cycle is called peak value C
In half cycle is called Instantaneous value D
None of these E

Question # 25

At resonance frequency the impedance of parallel resonance circuit is

Maximum A
Minimum B
Zero C
None of the above D

Question # 26

If we connect a A.C. volt meter to read A.C. voltage, It would read its:

RMS value A
Instantaneous value B
Valued average over a cycle C
Zero D
Both (B) and (C) E

Question # 27

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 # 28

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 # 29

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 # 30

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

Sr.#	Question	Answer
1	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
2	When the p-n junction is forward biased its resistance is of the order of	A. few mega ohms B. few kilo ohms C. few ohms D. few milli ohms
3	Average value of A.C voltage during one cycle is	A. 1 B. Zero C. Maximum D. Variable
4	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
5	The amplifier which us used to perform mathematical operations electronically is known as	A. calculator B. OP-AMP C. computer D. any one of them
6	The basic circuit element in D.C. circuit is:	A. A capacitor B. A resistor C. An inductor D. Both (A) and (C)
7	The waveform of alternating voltage is a:	A. Square B. Rectangular C. Saw-tooth D. Sinusoidal
8	The device which allows only the flow of an A.C. through a circuit is	A. Capacitor B. Inductor C. D.C. motor D. Battery
9	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
10	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

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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