Voltage dependent resistors are usually made from
A. Charcoal
B. Silicon carbide
C. Nichrome
D. Graphite
Answer: Option B
Solution (By Examveda Team)
Voltage dependent resistors (VDRs), also known as varistors, are semiconductor devices designed to protect electronic circuits from excessive voltage spikes and surges.Silicon carbide is commonly used as the material for VDRs due to its properties:
1. Non-linear resistance: Silicon carbide exhibits a non-linear relationship between voltage and current, which allows it to act as a variable resistor that decreases its resistance as voltage increases beyond a certain threshold.
2. High breakdown voltage: Silicon carbide can withstand high voltages, making it effective for protecting circuits against transient overvoltage conditions.
Option A: Charcoal is incorrect because charcoal is not suitable for making VDRs due to its poor electrical properties.
Option C: Nichrome is incorrect because nichrome is an alloy used in heating elements due to its high electrical resistance and heat resistance, but it is not used in VDRs.
Option D: Graphite is incorrect because graphite is a good conductor of electricity and is used in electrodes and other applications requiring high electrical conductivity, not in VDRs.
Therefore, the correct answer is
Silicon carbide. This Question Belongs to Electrical Engineering >> Current Electricity
Voltage Dependent Resistors (VDRs) Voltage dependent resistors (VDRs) are electronic components that have a variable resistance depending on the applied voltage. They are also known as varistors. VDRs are commonly used to protect electronic circuits from voltage surges and spikes. Materials used to make VDRs VDRs are made from materials with a non-linear resistance characteristic. Some of the materials commonly used to make VDRs include: • Silicon carbide • Zinc oxide • Metal oxide varistors (MOVs)
Correct answer is option B
not Nichrome
Correct answer is option B