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Semiconductor Electronic: Material, Devices And Simple Circuits — Physics STD 12 Science — Question

Bihar BoardEnglish MediumSTD 12 SciencePhysicsSemiconductor Electronic: Material, Devices And Simple Circuits4 Marks
Question

Rectifier is a device which is used for converting alternating current or voltage into direct current or voltage. Its working is based on the fact that the resistance of p-n junction becomes low when forward biased and becomes high when reverse biased. A half-wave rectifier uses only a single diode while a full wave rectifier uses two diodes as shown in figures (a) and (b).

  1. If the rms value of sinusoidal input to a full wave rectifier is $\frac{\text{V}_0}{\sqrt{2}}$ then the rms value of the rectifier's output is:

  1. $\frac{\text{V}_0}{\sqrt{2}}$

  2. $\frac{\text{V}_0^2}{\sqrt{2}}$

  3. $\frac{\text{V}_0^2}{2}$

  4. $\sqrt{2}\text{V}_0^2$

  1. In the diagram, the input ac is across the terminals A and C. The output across B and D is:

  1. Same as the input.
  2. Half wave rectified.
  3. Zero.
  4. Full wave rectified.
  1. A bridge rectifier is shown in figure. Alternating input is given across A and C. If output is taken across BD, then it is:

  1. Zero.
  2. Same as input.
  3. Half wave rectified.
  4. Full wave rectified.
  1. A p-n junction (D) shown in the figure can act as a rectifier. An alternating current source (V) is connected in the circuit. The current (I) in the resistor (R) can be shown by:

  1. With an ac input from 50Hz power line, the ripple frequency is:
  1. 50Hz in the de output of half wave as well as full wave rectifier.
  2. 100Hz in the de output of half wave as well as full wave rectifier.
  3. 50Hz in the de output of half wave and I 00Hz in de output of full wave rectifier.
  4. 100Hz in the de output of half wave and 50Hz in the de output of full wave rectifier.
✓

Answer

  1. (a) $\frac{\text{V}_0}{\sqrt{2}}$

Explanation:

Therms value of the output voltage at the load resistance, $\frac{\text{V}_0}{\sqrt{2}}.$

  1. (d) Full wave rectified.
  2. (a) Zero.
  3. (c)

Explanation:

The given circuit works as a half wave rectifier. In this circuit, we will get current through R when p-n junction is forward biased and no current when p-n junction is reverse biased. Thus the current (I) through resistor (R) will be shown in option (c).

  1. (c) 50Hz in the de output of half wave and I 00 Hz in de output of full wave rectifier.

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