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
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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 :
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Assertion (A) : A tunnel diode consists of simple p-n junction mode of degenerate semiconductor. The current voltage characteristics consists of three components and shows the negative differential region over part of the forward characteristics.
Reason (R) : In tunnel diode the p-side is highly doped and n-side is highly doped and also used as detector.
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 :
Important Questions from Types of Diode
For which of the following diodes when the voltage is increased the current flowing through it decreases?
Which of the following is the main application of Zener diode?
A tunnel diode is
When we tune in any desired station in a radio receiver by rotating the tuning control we vary
Which diode is used as a voltage regulator?
