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Q1. | What is the numerical aperture an optical fiber when critical angle is 30°? |

A. | 0.5 [Correct Answer] |

B. | 0.704 [Wrong Answer] |

C. | 0.866 [Wrong Answer] |

D. | 0.2 [Wrong Answer] |

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

⇒ An RLC series circuit has Q = 100 and ω

_{0}= 20 rad/sec. The bandwidth is

0.2 rad/sec

2 rad/sec

20 rad/sec

2000 rad/sec

⇒ The output resistance of a microphone is 20 ohms. It is to feed a line of impedance 320 ohms. To ensure maximum power transfer, the turn ratio of transformer is

16

256

2

4

⇒

**Assertion (A):** McMurray Bredford half bridge inverter uses complementary commutation

**Reason (R):** Three phase inverter can have two modes of operation.

Both A and R are correct and R is correct explanation of A

Both A and R correct but R is not correct explanation of A

A is correct but R is wrong

A is wrong but R is correct

⇒ If eddy current damping is to be used, the disc of instrument should be

non-conducting and non-magnetic

conducting and magnetic

conducting and non-magnetic

non-conducting and magnetic

⇒ The Laplace transform of a unit step function is

1

1 /

*s*

*s*

1 /

*s*

^{2}

⇒ The proper exponential form of - 0.0032 in FORTRAN 77 is

-3.2 E - 3

-0.0032

-0.00032 EI

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⇒ A typical value of

*g*

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TRUE

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⇒ Some possible disadvantages of high level modulation in TV transmitters are

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1 only

1 and 2 only

1, 2 and 3

2 and 3 only

⇒ A lossless transmission line is 50 cm long and operates at a frequency of 500 MHz. Inductance and capacitances present in a line are 0.5 μH/m and 200 pF/m. Phase constant and phase velocity are respectively.

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5p, 10

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31.4, 10

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31.4, 2p x 10

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⇒ If zeros at infinity are included in the count, the number of zeros of G(

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one more than the number of poles

one less than the number of poles

none of the above

⇒ A single phase semiconverter has a freewheeling diode. If the firing angle is a and the load is purely resistive, the periods of conduction and freewheeling respectively are

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p - a and a

p + a and 0

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⇒ An encoder converts decimal numbers to binary and other codes.

TRUE

FALSE

⇒ The high voltage level of a digital signal in positive logic is

1

0

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⇒ The output wave of a cycloconverter consists of a number of segments derived from the input wave.

TRUE

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⇒ The expression

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`A * A + B * B - 3.0 A * B `

`A * A + B * B - 3.0 * A * B`

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⇒ To draw dc equivalent circuit for a CE amplifier circuit we should

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⇒ The circuit shown in figure

low pass filter

high pass filter

band pass filter

band stop filter

⇒ For a two port network to be reciprocal

Z

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*y*

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*h*

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⇒ Which one is correct option about ROC?

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⇒ Which one of the following effects is used in measuring power?

Seeback

Ferrari

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⇒ In a JFET

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both the junctions are reverse biased

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⇒ The amplifier network is shown bel

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⇒ A device which converts BCD to seven segment is called

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multiplexer

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⇒ Consider a baseband binary PAM receiver shown below. The additive channel noise

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*f*) = N

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0.5 x

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⇒ Zero suppression is not used in actual practice.

TRUE

FALSE

⇒ Consider the following statements about Yagi Uda antenna

1 and 2 only

1, 2, 4 only

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⇒ Directivity and beamwidth is related as

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⇒ An

both

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⇒ The directive gain of a transmitting antenna is

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inversely proportional to wavelength

proportional to square of wavelength

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⇒ The dimensions of permittivity are

L

L

L

L

⇒ Zero suppression is not used in actual practice.

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FALSE

⇒ Consider the following statements about Yagi Uda antenna

- It is unidirectional
- Its gain is about 7 dB
- It is used at VLF
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1, 2, 4 only

1, 2, 3, 4

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⇒ Directivity and beamwidth is related as

D ∝ B

D ∝ 1/B

D ∝ B

D ∝ B

^{2}⇒ An

*m*derived low pass filter has*f*_{c}= 1000 Hz,*f*_{∞}= 1250 Hz and*m*= 0.6. If*m*is increased, thenboth

*f*_{c}and*f*_{∞}will increaseboth

*f*_{c}and*f*_{∞}will decrease*f*_{c}will remain constant but*f*_{∞}will decrease*f*_{c}will remain constant but*f*_{∞}will increase⇒ The directive gain of a transmitting antenna is

proportional to wavelength

inversely proportional to wavelength

proportional to square of wavelength

inversely proportional to square of wavelength

⇒ The dimensions of permittivity are

L

^{-3}M^{-1}T^{2}Q^{2}L

^{-1}M^{-1}T^{2}Q^{2}L

^{2}MT^{-1}Q^{-1}L

^{-2}M^{-1}T^{2}Q^{2}