In an unbiased p-n junction, holes diffuse from the p-region to n-region because ______. - Physics

Advertisements
Advertisements
MCQ
Fill in the Blanks

In an unbiased p-n junction, holes diffuse from the p-region to n-region because ______.

Options

  • free electrons in the n-region attract them.

  • they move across the junction by the potential difference.

  • hole concentration in p-region is more as compared to n-region.

  • All the above.

Advertisements

Solution

Hole concentration in p-region is more as compared to n-region.

Explanation:

The diffusion of charge carriers across a junction takes place from the region of higher concentration to the region of lower concentration. In this case, the p-region has a greater concentration of holes than the n-region. Hence, in an unbiased p-n junction, holes diffuse from the p-region to the n-region.

Concept: p-n Junction
  Is there an error in this question or solution?
Chapter 14: Semiconductor Electronics: Materials, Devices and Simple Circuits - Exercise [Page 497]

APPEARS IN

NCERT Physics Class 12
Chapter 14 Semiconductor Electronics: Materials, Devices and Simple Circuits
Exercise | Q 14.4 | Page 497
NCERT Physics Class 12
Chapter 14 Semiconductor Electronics: Materials, Devices and Simple Circuits
Exercise | Q 4 | Page 509

RELATED QUESTIONS

Explain briefly with the help of necessary diagrams, the forward biasing of a p-n junction diode. Also draw characteristic curves.


Explain briefly with the help of necessary diagrams, the  reverse biasing of a p-n junction diode. Also draw characteristic curves.


Draw a circuit diagram to study the input and output characteristics of an n-p-n transistor in its common emitter configuration. Draw the typical input and output characteristics.


How is a zener diode fabricated so as to make it a special purpose diode? Draw I-V characteristics of zener diode and explain the significance of breakdown voltage.

Explain briefly, with the help of a circuit diagram, how a p-n junction diode works as a half wave rectifier.


When a p-type impurity is doped in a semiconductor, a large number of holes are created, This does not make the semiconductor charged. But when holes diffuse from the p-side to the n-side in a p-n junction, the n-side gets positively charged. Explain.


The drift current in a reverse-biased p-n junction is increased in magnitude if the temperature of the junction is increased. Explain this on the basis of creation of hole-electron pairs.


The drift current in a p-n junction is


The diffusion current in a p-n junction is


Diffusion current in a p-n junction is greater than the drift current in magnitude


A hole diffuses from the p-side to the n-side in a p-n junction. This means that


In a p.n junction, the depletion region is 400 nm wide and an electric field of 5 × 105 V m−1 exists in it. (a) Find the height of the potential barrier. (b) What should be the minimum kinetic energy of a conduction electron which can diffuse from the n-side to the p-side?


In a p-n junction, a potential barrier of 250 meV exists across the junction. A hole with a kinetic energy of 300 meV approaches the junction. Find the kinetic energy of the hole when it crosses the junction if the hole approached the junction (a) from the p-side and (b) from the n-side.


Calculate the current through the circuit and the potential difference across the diode shown in figure. The drift current for the diode is 20 µA.


Find the currents through the resistance in the circuits shown in figure. 

(Assume that the resistance of each diode is zero in forward bias and is infinity in reverse bias.)


What are the readings of the ammeters A1 and A2 shown in figure. Neglect the resistance of the meters.

(Assume that the resistance of each diode is zero in forward bias and is infinity in reverse bias.)


Find the current through the resistance R in figure if (a) R = 12Ω (b) R = 48Ω.

(Assume that the resistance of each diode is zero in forward bias and is infinity in reverse bias.)


A diode, a resistor and a 50 Hz AC source are connected in series. The number of current pulses per second through the resistor is __________ .


Choose the correct option.

Current through a reverse-biased p-n junction increases abruptly at:


Answer in detail.

Discuss the effect of external voltage on the width of depletion region of a p-n junction.


If in a p-n junction diode, a square input signal of 10 V is applied as shown Then the output signal across RL will be ______

 


The depletion layer in the p-n junction diode is caused by ______.


In a semiconductor diode, the barrier potential offers opposition to only ______.


p-n junction diode is formed


Zener breakdown occurs in a p-n junction having p and n both:


Share
Notifications



      Forgot password?
Use app×