Assertion (A) : The Gunn diode characteristics shows the region of negative resistance. Reason (R) : The Gunn diode is made of n-type and p-type degenerate semiconductor. Select your answer using the codes given below.
(A) is true, but (R) is false.
To solve the question regarding the assertion and reason about the Gunn diode, let's first understand the relevant concepts:
Conceptual Explanation:
- Gunn Diode and Negative Resistance: A Gunn diode is a type of diode used in high-frequency electronics. It is unique because it exhibits a region of negative differential resistance in its current-voltage characteristics. This means that an increase in voltage across the diode leads to a decrease in current, which is utilized to generate microwave frequencies.
- Structure of a Gunn Diode: Contrary to typical semiconductor devices, the Gunn diode is not made by junctions of p-type and n-type semiconductors. Instead, it is formed solely from n-type semiconductor material, often gallium arsenide (GaAs) or indium phosphide (InP). The diode operates on the Gunn effect, which relates to the transfer of electrons between energy valleys in the semiconductor's conduction band.
Analysis of Assertion and Reason:
- Assertion (A): The Gunn diode characteristics show the region of negative resistance.
This statement is true because the Gunn diode naturally exhibits negative differential resistance, which is exploited to produce microwave frequencies. - Reason (R): The Gunn diode is made of n-type and p-type degenerate semiconductor.
This statement is false because Gunn diodes do not have a p-n junction; they are constructed from a single type of semiconductor (n-type). The assertion mistakenly suggests a composition involving both n-type and p-type semiconductors, which is not the case.
Conclusion:
Based on the analysis, the correct answer is: (A) is true, but (R) is false.
Similar Questions
A PIN diode can not be used as
i. Microwave switch
ii. Microwave mixer
iii. Microwave detectorWhich is correct ?
________ diode is not used as a microwave mixer or detector.
Match the given lists :
List – I (Name of the Device) List – II (Application) a. Diode i. Rectification b. Tunnel diode ii. Microwave switching c. Zener diode iii. An oscillator d. PIN diode iv. Voltage regulation Codes :
Varacter diodes have the following properties :
A. Junction capacitance varies with bias voltage
B. Junction capacitance varies with time
C. Non linearity of varacter diodes makes them suitable for frequency multipliers
D. Linearity of varactor diode makes them suitable for frequency multipliers.
Choose the correct answer from the options given below:
In a tunnel diode, the degeneracy on the n-side can be expressed as
The static current voltage characteristics of a tunnel diode consist of
(a) Tunneling current and thermal current
(b) Thermal current and excess current
(c) Tunneling current only
(d) Tunneling current, excess current and thermal current
Out of these which are correct ?
Match the following :
List – I List – II a. Gunn diode i. degenerate silicon b. Tunnel diode ii. n-type Ga As c. BJT iii. Silicon d. Diode (P-N junction) iv. \(I_o\left[\exp\left(\dfrac{qV}{kT}\right)-1\right]\) Choose the correct answer from the codes given below:
A TRAPATT diode has the doping concentration NA = 2 x 1015/cm3 and a current density of 20 kA/cm2. The value of avalanche zone velocity is given by :
Which of the following statements are correct for Tunnel Diode ?
(a) 1 impurity atom in 103 atoms
(b) Very high doping in both p and n regions
(c) 1 impurity atom in 108 atoms
(d) used as a voltage controlled devices
Out of the above, the following is the correct answer :
Which of the following statements are true for a zener diode ?
(a) The voltage across the zener resistance is zero.
(b) The diode is used as a constant voltage device.
(c) The diode is used as a varactor diode.
(d) The diode is formed of heavily doped p and n-type semiconductor.
Options :
Important Questions from Types of Diode
A PIN diode can not be used as
i. Microwave switch
ii. Microwave mixer
iii. Microwave detectorWhich is correct ?
________ diode is not used as a microwave mixer or detector.
Match the given lists :
List – I (Name of the Device) List – II (Application) a. Diode i. Rectification b. Tunnel diode ii. Microwave switching c. Zener diode iii. An oscillator d. PIN diode iv. Voltage regulation Codes :
Varacter diodes have the following properties :
A. Junction capacitance varies with bias voltage
B. Junction capacitance varies with time
C. Non linearity of varacter diodes makes them suitable for frequency multipliers
D. Linearity of varactor diode makes them suitable for frequency multipliers.
Choose the correct answer from the options given below:
In a tunnel diode, the degeneracy on the n-side can be expressed as
