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Q1. | Skin effect occurs when a conductor carries current at____ frequencies. |

A. | Very low [Wrong Answer] |

B. | Low [Wrong Answer] |

C. | Medium [Wrong Answer] |

D. | High [Correct Answer] |

View Answer
Explanation:-
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**Also Read Similar Questions Below :**

⇒ The value of operator j2 is equal to

Zero

+1

-1

√-1

⇒ The ratio of the bandwidth to the resonance frequency is called the____ of the circuit.

Impedance

Susceptance

Quality factor

Selectivity

⇒ Selectivities of different resonance circuits are compared in terms of their

Impedances

Reactances

Frequencies

Band widths

⇒ Higher the Q of a series circuit

Broader its resonance curve

Narrower its pass band

Greater its band width

Sharper its resonace

⇒ While drawing vector diagram for a series circuit the reference vector is

Voltage

Current

Power

Phase angle

⇒ Which of the following waves has the highest value of peak factor '?

Square wave

Sine wave

Half wave rectifier sine wave

Triangular wave

⇒ The period of a wave is

The same as frequency

Time required to complete one cycle

Expressed in amperes

None of the above

⇒ At half power points of a resonance curve, the current is____ times the maximum current.

1/2

1/ √2

√2

2

⇒ Power factor of an inductive circuit is usually improved by connecting capacitor to it in

Parallel

Series

Either (A) or (B)

None

⇒ The power is measured in terms of decibles in case of

Electronic equipment

Transformers

Current transformers

Auto-transformers

⇒ The unit of frequency of an A.C. signal is

Cycle

Cycle-sec

Hertz

Hertz/sec

⇒ The ratio of active power to apparent power is known as ____ factor.

Demand

Load

Power

Form

⇒ In a series resonant circuit, the impedance of the circuit is

Minimum

Maximum

Zero

None of the above

⇒ The double energy transient occur in the

Purely inductive circuit

R-L circuit

R-C circuit

R-L-C circuit

⇒ In a R-L-C series circuit if voltage V across the circuit is reduced to half the current I will change to

2 I

I/2

3/4 I

5/8 I

⇒ The capacitors for power factor correction are rated in terms of

Voltage

VA

kW

kVAR

⇒ The form factor is the ratio of

Peak value to r.m.s. value

r.m.s. value to average value

Average value to r.m.s. value

None of these

⇒ Form factor for a sine wave is

1.414

0.707

1.11

0.637

⇒ Poor power factor results in all of the following EXCEPT.

Overloading of transformers

Overloading of altemators

Reduction in power losses

Reduction in load handling capacity of electrical system

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

Current

Voltage

Impedance

Reactance

⇒ In a circuit containing R, L and C, power loss can take place

C only

L only

R only

All of the above

⇒ How much r.m.s. current does a 300 W. 200V bulb take from the 200 V, 50 Hz power line ?

0.5A

1.5 A

2A

3A

⇒ A heater is rated as 230 V, 10 KW, AC. The value 230 V refers t

Average voltage

r.m.s. voltage

Peak voltage

None of these

⇒ Two waves of the same frequency have opposite phase when the phase angle between them is

360°

180°

90°

0°

⇒ The form factor of D.C. supply voltage is always

Zero

0.5

Unity

Infinite

⇒ The reflection co-efficient of the simplest standing wave is

+1

1

Zero

Infinity

⇒ The r.m.s. value of pure cosine function is

0.5 of peak value

0.707 of peak value

Same as peak value

Zero

⇒ A sine wave of voltage varies from zero to maximum of 200 V. How much is the voltage at the instant of 30° of the cycle ?

50V

82.8V

100V

173.2 V

⇒ The safest value of current the human body can carry for more than 3 second is

4 mA

9 mA

15 mA

25 mA

⇒ Two sinusoidal quantities are said to be phase quadrature, when their phase difference is

0

30°

45°

90°