Analog electronics circuits miscellaneous Easy Questions and Answers | Page - 26

Analog electronics circuits miscellaneous

In the shunt regulator of fig below the V_z = 8.2 V and V_BE = 0.7 V. The regulated output voltage V₀ is:

1. 11.8 V
1. 7.5 V
1. 12.5 V
1. 8.9 V

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From given figure
V₀ = V_Z + V_BE = 8.2 + 0·7 = 8·9 V

Correct Option: D

From given figure
V₀ = V_Z + V_BE = 8.2 + 0·7 = 8·9 V

63. The zener diode in the current shown in figure (A) has the characteristics shown in figure (B). If R₂ is the lowest load resistance to be used for regulated supply. Then to get load regulation, R₁ must be:

1. greater than V₀ + 0·01R₂
  (V_in – V₀)R₂
1. greater than (V_in – V₀)R₂
  V₀ – 0·01R₂
1. less than (V_in – V₀)R₂
  V₀ + 0·01R₂
1. less than V₀ + 0·01R₂
  (V_in – V₀)R₂

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Given that I_{z (max)} = 10 mA
and from figure I_L = V₀
R₂

Now, for good load regulation

Correct Option: C

Given that I_{z (max)} = 10 mA
and from figure I_L = V₀
R₂

Now, for good load regulation

Zener diode works on the principle of:

1. tunneling of charge carriers across the junction
1. thermionic emission
1. diffusion of charge carriers across the junction
1. hoppling of the charge carriers across the junction

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In zener diode the carriers are accelerated by electric field. When they collide with atoms they ionize the atom due to their kinetic energy. Hence an avalanche break down occurs due to the large increase in the number of carriers.
Hence alternative (A) is the correct choice.

Correct Option: A

In zener diode the carriers are accelerated by electric field. When they collide with atoms they ionize the atom due to their kinetic energy. Hence an avalanche break down occurs due to the large increase in the number of carriers.
Hence alternative (A) is the correct choice.

The ideal characteristic of a stabilizer is:

1. constant output voltage with low internal resistance
1. constant output voltage with high internal resistance
1. constant internal resistance with variable output voltage
1. None of these

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Voltage stabilizer (i.e. zener diode or other device, that suppresses variation in a D.C. voltage) is always connected in parallel with load, so ideally its internal resistance must be zero
Lower the value of R_z gives better constant voltage.
Hence alternative (A) is the correct choice.

Correct Option: A

Voltage stabilizer (i.e. zener diode or other device, that suppresses variation in a D.C. voltage) is always connected in parallel with load, so ideally its internal resistance must be zero
Lower the value of R_z gives better constant voltage.
Hence alternative (A) is the correct choice.

Consider the following statements regarding the circuit given in the figure below, where the output voltage is constant:
(i) V_in > the voltage at which the zener breaks down
(ii) i_L < the difference between I and I_z, current at which the zener breaks down
(iii) R_S < the zener nominal resistance of these statements

1. (i), (ii) and (iii) are correct
1. and (ii) are correct
1. and (iii) are correct
1. and (iii) are correct

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NA

Correct Option: B

NA