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Q1. | The specified maximum junction temperature of thyristors is about |

A. | 50°C [Wrong Answer] |

B. | 80°C [Wrong Answer] |

C. | 120°C [Correct Answer] |

D. | 200°C [Wrong Answer] |

View Answer
Explanation:-
Answer : CDiscuss it below :!! OOPS Login [Click here] is required to post your answer/resultHelp other students, write article, leave your comments |

**Also Read Similar Questions Below :**

⇒ A periodic voltage

*v*(

*t*) = 1 + 4 sin ω

*t*+ 2 cos ω

*t*is applied across a 1 ohm resistance. The power dissipated is

1 W

11 W

21 W

24.5 W

⇒ The switch in the circuit shown was on position

*a*for a long time, and is moved to position

*b*at time

*t*= 0. The current

*i*(

*t*) for

*t*> 0 is give

0.2

*e*

^{-125t}

*u*(

*t*) mA

20

*e*

^{-1250t}

*u*(

*t*) mA

0.2

*e*

^{-1250t}

*u*(

*t*) mA

20

*e*

^{-1000t}

*u*(

*t*) mA

⇒ 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.

5p, 2p x 10

^{8}m/sec

5p, 10

^{8}m/sec

31.4, 10

^{8}m/sec

31.4, 2p x 10

^{8}m/sec

⇒ In figure, the short circuit current through terminal AB wil

1.5 A

0.125

0.0833333333333333

0.0416666666666667

⇒ (2)

_{3}+ (3)

_{4}= (?)

_{5}

4

11

none of these

not possible

⇒ In a television camera tube, scanning of a picture is done

line by line from left to right

line by line from right to left

line by line from top to bottom

line by line from bottom to top

⇒ If σ is standard deviation, variation is

σ - 1

σ

^{1.5}

σ

^{2}

σ

^{3}

⇒ Which of the following needs DC forward voltage to emit light?

LED

LCD

Both LED as well as LCD

None of the above

⇒ The phase angle corresponding to λ/4 in a standing-wave pattern is

30°

90°

135°

180°

⇒ A single phase half wave controlled rectifier circuit has a free wheeling diode. The load is a combination of R and L. The firing angle is a. The period of conduction of SCR and free wheeling diode respectively are

a < ω

*t*< p and p < ω

*t*< (2p + a)

a < ω

*t*< p and p < ω

*t*< 2p

a < ω

*t*< (p + a) and (p + a) < ω

*t*< 2p

a < ω

*t*< p and p < ω

*t*< (2p - a)

⇒ In the given figure 15.6 shows a series, R - C circuit fed by a current source

*i*(

*t*). There is an initial voltage

*v*

_{0}. across the capacitor. The sy

is linear

is non linear

may be linear or non linear

is linear only if

*v*

_{0}is zero

⇒ A constant

*k*high pass p section has a characteristic impedance of 300 Ω at

*f*= ∞ . At

*f*=

*f*

_{c}, the characteristic impedance will be

zero

∞

300 Ω

more than 300 Ω

⇒ An unmodulated voltage 10

*V*effective is applied to a dioxide detector in which load resistance is 4 x 10

^{-5}ohms. A micrometer shows that the rectified DC current in this resistance is 30

*A*. The input resistance of the detector is

114 kW

336 kW

384 kW

455 kW

⇒ An antenna has a gain of 44 dB. Assuming that the main beam of the antenna is circular in cross-section the beamwidth will be

0.4456°

1.4456°

2.4456°

3.4456°

⇒ A waveguide operated below cut off frequency can be used as

phase shifter

an attenuator

an isolator

none

⇒ Figure represen

LED

Varistor

SCR

Diac

⇒ The spectral component of noise associated with

*k*

^{th}frequency is given, in the limit as Δ

*f*→ 0 by

*n*(

_{k}*t*) written as

*n*(

_{k}*t*) = C

_{k}cos (2p

*k*Δ

*ft*+ θ

_{k1, 2 only1, 3 only1, 2, 32, 3 only}

⇒ The attraction between the nucleus and valence electron of copper atom is

zero

weak

strong

either zero or strong

⇒ How many lines are there in address bus of 8085 μp?

6

8

12

16

⇒ A system is said to be static system, when present output depend upon

present I/P

presrent and past

present and future

past and future

⇒ Lead becomes a superconductor at

9.1 K

7 K

5 K

3 K

⇒ If the number of atoms per unit volume of a monoatomic gas changes, the dielectric constant still remains constant.

TRUE

FALSE

⇒ Tropospheric scatter propagation is not subject to any fading.

TRUE

FALSE

⇒ A full wave bridge diode rectifier uses diodes having forward resistance of 50 ohms each. The load resistance is also 50 ohms. The voltage regulations is

0.2

0.5

1

2

⇒ There is no hysteresis phenomenon is any dielectric material.

TRUE

FALSE

⇒ Under identical conditions, for a single modulating frequency, FM and PM are indistinguishable. Now if the modulating frequency is reduced, then

phase modulation index as well as frequency modulation index decrease

phase modulation index as well as frequency modulation index increase

phase modulation index will remain constant whereas frequency modulation index will increase

phase modulation index will decrease whereas frequency modulation index will remain constant

⇒ For a given operating frequency a waveguide has more power handling capacity than a coaxial line.

TRUE

FALSE

⇒ Colour code of carbon resistors has only two bands.

TRUE

FALSE

⇒ Forbidden energy gap in germanium at 0 K is about

10 eV

5 eV

2 eV

0.78 eV

⇒

Match the following:

List I (BHE, A0) | List II (Word is read/write) | ||
---|---|---|---|

A. | 0, 0 | 1. | 1 byte from/to odd address |

B. | 0, 1 | 2. | 1 byte from/to even address |

C. | 1, 0 | 3. | 16 bit word |

D. | 1, 1 | 4. | None |

A-1, B-2, C-3, D-4

A-3, B-1, C-2, D-4

A-2, B-3, C-4, D-1

A-4, B-1, C-2, D-3