When is a p-n junction said to be forward biased or what is meant by forward biasing of p-n junction? How does it affect resistance?

When is a p-n junction said to be forward biased or what is meant by forward biasing of p-n junction? How does it affect resistance?
by

1 Answer

Answer :

When the positive terminal of a cell is connected to p-side and negative terminal to the n-side of a p-n junction then it is said to be forward biased. It offers low resistance.
by

Related questions

When is a p-n junction said to be biased?

Description : When is a p-n junction said to be biased?

Last Answer : When an external source of e.m.f is connected to a p-n junction, it is said to be biased.

Why does a forward biased diode offer low resistance?

Description : Why does a forward biased diode offer low resistance?

Last Answer : The external voltage over comes the junction potential and provides an easy path for the flow of charges across the junction. Hence it offers low resistance.

When a P - N junction is forward biased

Description : When a P - N junction is forward biased  1.only electrons in N-region are injected into P-region 2.only holes in P-region are injected into N-region 3.majority carriers in each region are injected into the other region 4.minority current is reduced to zero 

Last Answer : When a P - N junction is forward biased majority carriers in each region are injected into the other region 

What is a p-n junction?

Description : What is a p-n junction?

Last Answer : The junction that is obtained when a p-type semiconductor and an n-type semiconductor are kept in contact is called p-n junction.

If PN junction is forward biased its resistance is (a) Zero (b) Infinity (c) A few ohm (d) A few kilo ohms

Description : If PN junction is forward biased its resistance is (a) Zero (b) Infinity (c) A few ohm (d) A few kilo ohms

Last Answer : c) A few ohm

Why does a reversed biased diode offer high resistance?

Description : Why does a reversed biased diode offer high resistance?

Last Answer : The charge carriers are repelled from the junction and no current flows through the junction. Thus the diode offers a high resistance.

What is meant by junction potential?

Description : What is meant by junction potential?

Last Answer : The potential difference that is established due to the diffusion of electrons and holes across the boundary in the p-n junction is called junction voltage. The junction potential is 0.7v for Silicon and 0.3v for Germanium.

Write about the biasing of a transistor.

Description : Write about the biasing of a transistor.

Last Answer : Emitter base junction is forward biased while collector base junction is reverse biased.

In the reverse biased p-n junction, the current is of the order of (a) Ampere (b) Milliampere (c) Microampere (d) Nano-ampere

Description : In the reverse biased p-n junction, the current is of the order of (a) Ampere (b) Milliampere (c) Microampere (d) Nano-ampere

Last Answer : (d) Nano-ampere

P-n junction when reversed biased acts as a (a) Capacitor (b) inductor (c) on switch (d) off switch

Description : P-n junction when reversed biased acts as a (a) Capacitor (b) inductor (c) on switch (d) off switch

Last Answer : d) off switch

The capacitance of reverse biased P-N junction

Description : The capacitance of reverse biased P-N junction  1. Decreases with increasing the reverse bias 2. Increases with increasing the reverse bias 3. Depends only on reverse saturation current 4. Makes the P-N junction more effective at high frequencies 

Last Answer : The capacitance of reverse biased P-N junction Decreases with increasing the reverse bias

When a PN junction is forward biased, what happens to the depletion region?

Description : When a PN junction is forward biased, what happens to the depletion region?

Last Answer : The depletion region decreases.

For normal operation of a transistor, the collector base junction is kept (a) Unbiased (b) forward biased (c) reverse biased (d) none

Description : For normal operation of a transistor, the collector base junction is kept (a) Unbiased (b) forward biased (c) reverse biased (d) none

Last Answer : (c) reverse biased

Describe the working of PN junction diode with neat sketch under forward biased condition.

Description : Describe the working of PN junction diode with neat sketch under forward biased condition.

Last Answer : If the p-region (anode) is connected to the positive terminal of the external DC source and nside (cathode) is connected to the negative terminal of the DC source then the biasing ... The large number of majority carriers crossing the junction constitutes a current called as the forward current.

For the active mode BJT operation (A) Emitter Base Junction is Forward Biased and Collector

Description : For the active mode BJT operation (A) Emitter Base Junction is Forward Biased and Collector Base Junction is Forward Biased (B) Emitter Base Junction is Reverse Biased and Collector Base Junction ... Biased (D) Emitter Base Junction is Reverse Biased and Collector Base Junction is Forward Biased

Last Answer : For the active mode BJT operation Emitter Base Junction is Forward Biased and Collector Base Junction is Reverse Biased.

A forward-biased PN-junction,

Description : A forward-biased PN-junction,  (A) results in increase in diffusion current  (B) results in increase in drift current  (C) results in decrease in drift current  (D) results in decrease in diffusion current

Last Answer : A forward-biased PN-junction,  results in increase in diffusion current 

What is a semiconductor diode or junction diode?

Description : What is a semiconductor diode or junction diode?

Last Answer : A diode is a single crystal of semiconducting material which is doped one side with a donor impurity and the other side with acceptor impurity.

Define i)P-N junction diode ii) Depletion layer iii)Forward bias iv)Reverse bias of P-N junction diode

Description : Define i)P-N junction diode ii) Depletion layer iii)Forward bias iv)Reverse bias of P-N junction diode

Last Answer : i)P-N junction diode: It is a semiconductor device in which half of its region is P-type and other half is N-type.  ii) Depletion layer: The region where free electrons and free holes are absent ... and negative terminal is connected to p-side of p-n junction diode, it is said to be reverse bias.

Explain the forward bias characteristics of a P-N Junction diode.

Description : Explain the forward bias characteristics of a P-N Junction diode. 

Last Answer : forward and reverse characteristics of P-N junction diode.

A bipolar junction transistor (BJT) is used as a power control switch by biasing it in the cut-off region

Description : A bipolar junction transistor (BJT) is used as a power control switch by biasing it in the cut-off region (OFF state) or in the saturation region (ON state). In the ON state, for ... base-collector junction is reverse biased (D) both the base-emitter and base-collector junctions are forward biased

Last Answer : A BJT is as a power control switch by biasing it in cut-off region (OFF state) or in the saturation region (ON state). In  ON state, for BJT both the base-emitter and base- collector junctions are forward biased

When the diode is forward biased, it is equivalent to a. An off switch b. An On switch c. A high resistance d. None of the above

Description : When the diode is forward biased, it is equivalent to a. An off switch b. An On switch c. A high resistance d. None of the above

Last Answer : b. An On switch

Draw V-I characteristics of p-n junction diode? Define static and dynamic resistance of diode.

Description : Draw V-I characteristics of p-n junction diode? Define static and dynamic resistance of diode.

Last Answer : Static Resistance: The resistance offered by a p-n junction diode when it is connected to a DC circuit is called static resistance.  (OR) It is the ratio of DC voltage applied across diode ... The dynamic resistance of a diode is the ratio of change in voltage to the change in current. 

In a reverse biased PN-junction, which current carriers cause leakage current?

Description : In a reverse biased PN-junction, which current carriers cause leakage current?

Last Answer : The minority carriers

What is meant by superconductivity?

Description : What is meant by superconductivity?

Last Answer : The property by which certain materials show almost zero resistance at a very low temperature is called superconductivity. Ex: The resistance of mercury drops abruptly to zero at 4.2K

What is meant by depletion region?

Description : What is meant by depletion region?

Last Answer : The thin region around the junction containing immobile positive and negative charges is called depletion region.

What is meant by doping?

Description : What is meant by doping?

Last Answer : The process of adding dopants to enhance the conductivity of semiconductors is called doping.

Explain the formation of a p-type semiconductor.

Description : Explain the formation of a p-type semiconductor.

Last Answer : When a small amount of a trivalent impurity like Boron, Indium, Aluminium or Gallium is added to a tetra valant element like Silicon or Germanium, three electrons of each impurity atoms ... and becomes n-type semiconductor. In an ntype semiconductor the majority charge carriers are holes.

Explain the formation of an n-type semiconductor.

Description : Explain the formation of an n-type semiconductor.

Last Answer : When a small amount of a penta valant impurity like antimony, arsenic or phosphorous is added to a tetra valant element like Silicon or Germanium, four out of five electrons of each impurity ... becomes an n-type semiconductor. In an n-type semiconductor the majority charge carriers are electrons.

How do you find the p.d across a resistor?

Description : How do you find the p.d across a resistor?

Last Answer : Whats p.d

The device in figure 'B' shown in the illustration will conduct when the ____________. EL-0067 A. base-emitter is forward biased and the collector-base is reverse biased B. anode-cathode is forward biased and the cathode-gate is forward biased C. source-gate is forward biased and the gate-drain is reversed biased D. terminal 1-2 is forward biased and the emitter-terminal 1 is reverse biased

Description : The device in figure 'B' shown in the illustration will conduct when the ____________. EL-0067 A. base-emitter is forward biased and the collector-base is reverse biased B. anode-cathode is forward ... is reversed biased D. terminal 1-2 is forward biased and the emitter-terminal 1 is reverse biased

Last Answer : Answer: B

A device used to avoid the relay destroying the op-amp is A. diode B. LED C. reverse bias diode D. forward biased diode

Description :  A device used to avoid the relay destroying the op-amp is A. diode B. LED C. reverse bias diode D. forward biased diode

Last Answer : reverse bias diode

When an SCR is forward biased, what is needed to cause it to conduct?

Description : When an SCR is forward biased, what is needed to cause it to conduct?

Last Answer : A gate signal.

A light emitting diode emits light only when (a) Reversed biased (b) forward biased (c) unbiased (d) none

Description : A light emitting diode emits light only when (a) Reversed biased (b) forward biased (c) unbiased (d) none

Last Answer : (b) forward biased

When the diode is forward biased, it is equivalent to

Description : When the diode is forward biased, it is equivalent to

Last Answer : When the diode is forward biased, it is equivalent to An On switch

What is meant by saying at what current is transistor biased?

Description : What is meant by saying at what current is transistor biased?

Last Answer : Ans-Bias current of a transistor is the preset DC current when no input voltage signal is applied to it.

In the depletion region in the P-N junction there are: a) No charges b) No current c) No mobile charges d) No electron

Description : In the depletion region in the P-N junction there are: a) No charges b) No current c) No mobile charges d) No electron

Last Answer : Ans: C

The width of depletion layer of a P-N junction – (1) decreases with light doping (2) increases with heavy doping (3) is independent of applied voltage (4) is increased under reverse bias

Description : The width of depletion layer of a P-N junction – (1) decreases with light doping (2) increases with heavy doping (3) is independent of applied voltage (4) is increased under reverse bias

Last Answer : (4) is increased under reverse bias Explanation: The total width of the depletion region is a function of applied reverse-bias and impurity concentration. Forward bias decreases the depletion region width whilst reverse bias increases it.

When two semiconductors of p-and ntype are brought in contact, they form p-n junction which acts like a/an – (1) Conductor (2) Oscillator (3) Rectifier (4) Amplifier

Description : When two semiconductors of p-and ntype are brought in contact, they form p-n junction which acts like a/an – (1) Conductor (2) Oscillator (3) Rectifier (4) Amplifier

Last Answer : (3) Rectifier Explanation: P-n junction is a device which flows current in one direction when it is forward biased and when it is reverse biased it doesn't flow any current through it. So it ... (AC), which periodically reverses direction, to direct current (DC), which flows in only one direction.

The waveform of a certain signal can be studied by – (1) Spectrometer (2) Cathode ray oscilloscope (3) p - n junction diode (4) Sonometer

Description : The waveform of a certain signal can be studied by – (1) Spectrometer (2) Cathode ray oscilloscope (3) p - n junction diode (4) Sonometer

Last Answer : (4) Sonometer Explanation: A spectrometer is an instrument used to measure properties of light over a specific portion of the electromagnetic spectrum. Cathode ray oscilloscope is an electronic display ... electron beam that is used to produce visible patterns or graphs on a phosphorescent screen.

In the illustrated amplifier, the base of the transistor is what type of material? EL-0022 A. N type B. P type C. metal oxide insulator D. alloy junction material

Description : In the illustrated amplifier, the base of the transistor is what type of material? EL-0022 A. N type B. P type C. metal oxide insulator D. alloy junction material

Last Answer : Answer: A

Why gold is added to the p-n junction?

Description : Why gold is added to the p-n junction?

Last Answer : Ans-To reflect heat. To reduce the recombination time.

On increasing the reverse bias to a large value in a p-n junction diode current (a) Increases slowly (b) Remains fixed (c) Suddenly increases (d) Decreases slowly

Description : On increasing the reverse bias to a large value in a p-n junction diode current (a) Increases slowly (b) Remains fixed (c) Suddenly increases (d) Decreases slowly

Last Answer : (c) Suddenly increases

Which is the most important building block of electronic devices? (a) Diode (b) p-n junction (c) transistor (d) rectifier

Description : Which is the most important building block of electronic devices? (a) Diode (b) p-n junction (c) transistor (d) rectifier

Last Answer : b) p-n junction

A transistor has (A) One p-n junction. (B) Two p-n junction. (C) Four p-n junction. (D) Five p-n junction.

Description : A transistor has (A) One p-n junction. (B) Two p-n junction. (C) Four p-n junction. (D) Five p-n junction.

Last Answer : (B) Two p-n junction.

P-N junction is (A) a rectifier. (B) an amplifier. (C) an Oscillator. (D) a Coupler.

Description : P-N junction is (A) a rectifier. (B) an amplifier. (C) an Oscillator. (D) a Coupler.

Last Answer : (A) a rectifier.

Barrier potential in a P-N junction is caused by (A) Thermally generated electrons and holes. (B) Diffusion of majority carriers across the junction. (C) Migration of minority carriers across the junction. (D) Flow of drift current.

Description : Barrier potential in a P-N junction is caused by (A) Thermally generated electrons and holes. (B) Diffusion of majority carriers across the junction. (C) Migration of minority carriers across the junction. (D) Flow of drift current.

Last Answer : (B) Diffusion of majority carriers across the junction.

List four specifications of zener diode or P- N junction diode.

Description : List four specifications of zener diode or P- N junction diode.

Last Answer : Specifications of zener diode: 1. Zener voltage 2. Power dissipation 3. Maximum power dissipation PD(max) 4. Breakdown current 5. Dynamic resistance 6. Maximum reverse current. (OR) ... Reverse saturation current 5. Power dissipation 6. Junction temperature 7. Peak inverse voltage (PIV)

Write two applications of P-N junction diode and zener diode.

Description : Write two applications of P-N junction diode and zener diode. 

Last Answer : Application of P-N junction diode: Used in rectifier circuit Used in clipping and clamping circuit. Used for A.M detection Used for voltage multiplier. Application of Zener diode: It is ... . Used in protection circuits for MOSFET. Used in pulse amplifier. Used in clipping circuits.

Draw and explain V-I characteristics of a P-N junction diode.

Description : Draw and explain V-I characteristics of a P-N junction diode.

Last Answer : V-I Characteristics of a P-N junction: V-I characteristics of a Diode: The V-I characteristics can be divided in two parts. 1. Forward characteristics. 2. Reverse ... plot a graph with reverse voltage on horizontal axis and current on vertical axis, we obtain reverse characteristics.

Compare P-N junction and Zener Diode.

Description : Compare P-N junction and Zener Diode.

Last Answer : P-N junction Zener Diode It conducts in only in one direction.  It conducts in both the directions. It is always operated in forward bias condition. It is always operated in ... . It cannot be used for rectification, but commonly used for voltage regulation