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

Question # 1

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 # 2

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 # 3

The phase angle of a series RLC circuit at resonance is

180° A
90° B
0° C
None of the these D

Question # 4

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 # 5

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 # 6

Conversion of alternating current into direct current is called

amplification A
rectification B
conduction C
polarization D

Question # 7

At resonance frequency the impedance of parallel resonance circuit is

Maximum A
Minimum B
Zero C
None of the above D

Question # 8

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 # 9

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 # 10

In which of the following diodes when an electron combines with a hole during the forward biasing, photon of visible light is emitted.

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

Question # 11

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 # 12

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 # 13

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 # 14

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 # 15

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 # 16

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 # 17

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 # 18

In which of the following components, pn-junction is used

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

Question # 19

SI unit of impedance is

hertz A
henry B
ampere C
ohms D

Question # 20

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 # 21

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

0° A
90° B
180° C
270° D

Question # 22

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 # 23

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 # 24

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 # 25

Which of the following has a great concentration of impurity

base A
emitter B
collector C
none of these D

Question # 26

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 # 27

Electromagnetic waves transmit energy equal to

1/2 mv² A
m_oc² B
hf/c C
hf D

Question # 28

OP-AMP has the following input terminals

one A
two B
three C
four D

Question # 29

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 # 30

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

0° A
90° B
70° C
45° D

Sr.#	Question	Answer
1	A diode characteristic curve is a plot between	A. current and time B. voltage and time C. voltage and current D. forward voltage and reversed voltage
2	Conversion of alternating current into direct current is called	A. amplification B. rectification C. conduction D. polarization
3	In frequency modulation (FM), the carrier waves amplitude	A. Remains constant B. Increase C. Decreases D. None of these
4	The open loop gain of OP-AMP is of the order of	A. 10² B. 10³ C. 10⁴ D. 10⁵
5	Alternating current can be transmitted:	A. To long distance B. At very high cost C. At very low cost D. Both (A) and (C)
6	At higher frequency of the alternating current, the capacitive reactance X_c	A. Increases B. Decreases C. Remains the same D. Increases only when the voltage increases
7	In a transistor, if the central region is n-type, then this type of transistor is known as	A. n-p-n transistor B. p-n-p transistor C. either of these D. none of these
8	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
9	The total reactance of a series RLC circuit at resonance is	A. zero B. Equal to the resistance C. Infinity D. Capacitive
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

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

The R1= infinity and R2= 0, then the gain of non-inverting amplifier is

The phase angle of a series RLC circuit at resonance is

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

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

Conversion of alternating current into direct current is called

At resonance frequency the impedance of parallel resonance circuit is

In half wave rectification

Alternating current can induce voltage because it has a

In which of the following diodes when an electron combines with a hole during the forward biasing, photon of visible light is emitted.

If the value of C in a series RLC circuit is increased, the resonant frequency

During the positive half-cycle in the half-wave rectification,the diode

For a n-p-n transistor, the conventional current equation can be written as

The closed loop gain of the inverting amplifier is written as

The value of the potential difference across the depletion region for the case of germanium is

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

The r.m.s. value of alternating current is equal to its maximum value at angle of

In which of the following components, pn-junction is used

SI unit of impedance is

Which one of the following Electro-magnetic wave have the highest frequency and shortest wave-length

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

The RMS value of alternating current is:

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

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

Which of the following has a great concentration of impurity

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

Electromagnetic waves transmit energy equal to

OP-AMP has the following input terminals

The closed loop gain of the non-inverting amplifier is given by

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

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The R₁= infinity and R₂= 0, then the gain of non-inverting amplifier is

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

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