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

Question # 1

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 # 2

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 # 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

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 # 5

In describing functions of digital systems, a closed switch will be shown as

0 A
1 B
low C
any one of these D

Question # 6

At higher frequency of the alternating current, the capacitive reactance X_c

Increases A
Decreases B
Remains the same C
Increases only when the voltage increases D

Question # 7

Which of the following diode is used to derive the current in external circuit when light is incident in the circuit

photo diode A
light emitting diode B
photo voltaic cell C
none of these D

Question # 8

Which of the following diode is used for the detection of light

photo diode A
light emitting diode B
photo voltaic cell C
all of them D

Question # 9

In RLC series circuit, resonance occurs when

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

Question # 10

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 # 11

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 # 12

At resonance, the impedance of RLC series circuit is

Maximum A
Zero B
Minimum C
Determinate D

Question # 13

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 # 14

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 # 15

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 # 16

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 # 17

When the emitter-base junction of a transistor is reverse biased, collector current

Reverses A
Increases B
Decreases C
Stops D

Question # 18

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 # 19

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 # 20

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 # 21

The device which allows only the flow of an A.C. through a circuit is

Capacitor A
Inductor B
D.C. motor C
Battery D

Question # 22

Transmitting antenna emits

Magnetic waves A
Electric waves B
Electromagnetic waves C
Sound waves D

Question # 23

The circuit which is used to smooth the output voltage of the full-wave rectification is known as

transformer A
rectifier B
filter C
none of these D

Question # 24

At resonance frequency the impedance of parallel resonance circuit is

Maximum A
Minimum B
Zero C
None of the above D

Question # 25

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 # 26

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 # 27

During the negative half-cycle of the half-wave rectification, the diode

does not conduct A
conducts B
either of these C
none of these D

Question # 28

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 # 29

An A.C. voltage is applied across the inductor. When the frequency of the voltage is increased, the current

Decreases A
Increases B
Does not change C
Momentarily goes to zero D

Question # 30

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

Sr.#	Question	Answer
1	The average of A.C. current and voltage over a complete cycle is	A. Maximum B. zero C. Neither zero nor maximum D. None of these
2	The bridge circuit of full wave rectification uses	A. one diode B. two diode C. three diode D. four diode
3	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
4	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
5	To design a resonant circuit of frequency 100 KHz with an inductor of inductance 5 mH, we need a capacitor of capacitance	A. 5.07 pF B. 50 pF C. 0.507 pF D. 507 pF
6	In frequency modulation (FM), the carrier waves amplitude	A. Remains constant B. Increase C. Decreases D. None of these
7	The phase at the positive peak of an A.C. cycle is:	A. 0º B. 90º C. 180º D. 0 andᏘ
8	The waveform of alternating voltage is a:	A. Square B. Rectangular C. Saw-tooth D. Sinusoidal
9	If 250V is the RMS value of alternative voltage, then its peak value V_owill be:	A. 353.5V B. 250V C. 175V D. zero
10	The length of rotating vector (on a certain scale) represents the:	A. Peak value of alternating quantity B. RMS value of alternating quantity C. Instantaneous value of alternating quantity D. Either (B) or (C)

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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