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

Question # 1

In RLC series circuit, resonance occurs when

X_{L > Xc} A
X_{L < Xc} B
X_{L = Xc} C
None of these D

Question # 2

At resonance, the impedance of RLC series circuit is

Maximum A
Zero B
Minimum C
Determinate D

Question # 3

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 # 4

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 # 5

Chock consumes externally small

Charge A
Current B
Power C
Potential D

Question # 6

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 # 7

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 # 8

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 # 9

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 # 10

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 # 11

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 # 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

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 # 14

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 # 15

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 # 16

The total reactance of a series RLC circuit at resonance is

zero A
Equal to the resistance B
Infinity C
Capacitive D

Question # 17

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 # 18

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 # 19

The amplifier which us used to perform mathematical operations electronically is known as

calculator A
OP-AMP B
computer C
any one of them D

Question # 20

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 # 21

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 # 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 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 # 24

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 # 25

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 # 26

In half wave rectification

both halves of the input voltage is used A
only one half of the input voltage is used B
either of these C
none of these D

Question # 27

The power factor of resonant series circuit is

1 A
0 B
-1 C
0.5 D

Question # 28

In a transistor, the central region is called

collector A
emitter B
base C
none of them D

Question # 29

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 # 30

Which one of the following waves belongs to electromagnetic spectrum

Radio and TV waves A
Radar waves B
Micro waves C
All of them D

Sr.#	Question	Answer
1	A changing magnetic flux creates around itself	A. An electromotive force B. An electric field (changing electric flux) C. Magnetic field D. None of the above
2	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
3	At resonance, the impedance of RLC series circuit is	A. Maximum B. Zero C. Minimum D. Determinate
4	During the positive half-cycle in the half-wave rectification,the diode	A. does not conduct B. conducts C. either of these D. neither of these
5	The phase at the positive peak of an A.C. cycle is:	A. 0º B. 90º C. 180º D. 0 andᏘ
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 one of the following is correct?	A. V_o= 1.414 V_rms B. I_ams= 1.414 I_o C. VO = 10.70 Vrms D. Both a and b
8	Alternating current is produced by a voltage source which polarity:	A. Remains the same B. Reverse after period T C. Keeps on reversing with time D. Reverse after every time interval T/2
9	OP-AMP has the following input terminals	A. one B. two C. three D. four
10	Chock consumes externally small	A. Charge B. Current C. Power D. Potential

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