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:
A and C only
To solve the given question regarding the properties of varactor diodes, let's first understand what a varactor diode is and its key properties.
Understanding Varactor Diodes:
Varactor diodes, also known as varicap diodes, are a type of semiconductor diode whose junction capacitance varies with the applied reverse bias voltage. This property is used in electronic tuning circuits, such as voltage-controlled oscillators, frequency modulators, and frequency multipliers.
Analysis of the Given Statements:
- Junction capacitance varies with bias voltage (Statement A): This is true. The capacitance of a varactor diode is dependent on the reverse bias voltage applied across its junction. As the voltage increases, the capacitance decreases.
- Junction capacitance varies with time (Statement B): This statement is incorrect. The capacitance primarily varies with the bias voltage and not directly with time.
- Non-linearity of varactor diodes makes them suitable for frequency multipliers (Statement C): This is true. The non-linear nature of the varactor diode's capacitance-voltage relationship allows it to be used for frequency multiplication of the input signal.
- Linearity of varactor diode makes them suitable for frequency multipliers (Statement D): This is incorrect. Varactor diodes are inherently non-linear, which is why they are used in applications like frequency multipliers.
Conclusion:
The correct answer is A and C only.
Therefore, the correct properties of varactor diodes related to the context given are:
- The junction capacitance varies with bias voltage.
- The non-linearity makes them suitable for frequency multipliers.
This analysis correctly excludes options B and D, affirming that junction capacitance does not vary directly with time and that linearity does not make varactor diodes suitable for frequency multiplication.
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 :
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 :
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 :
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 :
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 ?
