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 :
6.25 x 107 cm/s
To find the value of the avalanche zone velocity for the given TRAPATT diode, we need to use the relationship between current density (\( J \)), doping concentration (\( N_A \)), charge of an electron (\( q \)), and the avalanche zone velocity (\( v \)). The formula that relates these variables is:
\(J = q \cdot N_A \cdot v\)
Where:
Given:
Plug the known values into the equation:
\(20 \times 10^3 = 1.6 \times 10^{-19} \times 2 \times 10^{15} \times v\)
Simplifying the equation to solve for \(v\):
\(v = \frac{20 \times 10^3}{1.6 \times 10^{-19} \times 2 \times 10^{15}}\)
Calculating the right side:
\(v = \frac{20 \times 10^3}{3.2 \times 10^{-4}}\)
\(v \approx 6.25 \times 10^7 \, \text{cm/s}\)
Thus, the avalanche zone velocity of the TRAPATT diode is \(6.25 \times 10^7 \, \text{cm/s}\).
This corresponds to the correct answer: 6.25 x 107 cm/s.
A PIN diode can not be used as
i. Microwave switch
ii. Microwave mixer
iii. Microwave detector
Which 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:
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.
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 :
A PIN diode can not be used as
i. Microwave switch
ii. Microwave mixer
iii. Microwave detector
Which 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