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

Question # 1

The basic circuit element in A.C. circuits are:

Resistor and capacitor A
Resistor and Inductor B
Capacitor only C
Both (B) and (C) D
None of these E

Question # 2

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 # 3

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

Voltage A
Current B
Impedance C
Reactance D

Question # 4

Average value of A.C voltage during one cycle is

1 A
Zero B
Maximum C
Variable D

Question # 5

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 # 6

Chock consumes externally small

Charge A
Current B
Power C
Potential D

Question # 7

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 # 8

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 # 9

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 # 10

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 # 11

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 # 12

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 # 13

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 # 14

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 # 15

At resonance frequency the impedance of parallel resonance circuit is

Maximum A
Minimum B
Zero C
None of the above 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

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 # 18

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 # 19

Most OP-AMP operates with

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

Question # 20

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 # 21

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 # 22

OP-AMP has the following input terminals

one A
two B
three C
four D

Question # 23

The RMS value of alternating current is:

0.7 times at the peak value A
0.5 times the peak value B
0.7 times the Instantaneous value C
Equal to maximum voltage D
None of these E

Question # 24

A sinusoidally alternating voltage or current can be graphically represented by a:

Vector A
Rotating vector B
Clockwise vector C
Anticlockwise voltage vector D
None of these E

Question # 25

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

10² A
10³ B
10⁴ C
10⁵ D

Question # 26

In series RC circuit when R=X_c, then the phase angle is

0° A
90° B
70° C
45° D

Question # 27

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 # 28

When the p-n junction is forward biased its resistance is of the order of

few mega ohms A
few kilo ohms B
few ohms C
few milli ohms D

Question # 29

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 # 30

The magnitude of alternative voltage V:

Always increase A
Always decrease B
Remains constant C
Does not remain constant D
None of these E

Sr.#	Question	Answer
1	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
2	Nowadays, Most of the electric energy is produced by the A.C. generators using:	A. Hydal water B. Geothermal energy C. Solar energy D. Biomass
3	The bridge circuit of full wave rectification uses	A. one diode B. two diode C. three diode D. four diode
4	The basic circuit element in D.C. circuit is:	A. A capacitor B. A resistor C. An inductor D. Both (A) and (C)
5	In frequency modulation (FM), the carrier waves amplitude	A. Remains constant B. Increase C. Decreases D. None of these
6	A signal is amplified at the output without any change of phase, if it is applied at the	A. inverting input B. non-inverting input C. at any of the input D. none of these
7	An A.C. voltmeter read 250 volts. The frequency of alternating is 50 Hz, the peak value of voltage is	A. 3525.0 volts B. 35.35 volts C. 353.5 volts D. 3.535 volts
8	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
9	The value of current gain of n-p-n transistor is of the order of	A. tens B. hundreds C. thousands D. ten thousands
10	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

Latest Educational News Stories

Pakistan's Largest Database of Colleges and Universities

BS Programs

University Past Papers

University Results

Exam Results 2024

Study Abroad Programs and Opportunities for Pakistani Students

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