Zener Diode MCQ & Answers [PDF Download]
A Zener diode with Vz = 6.8V and Pz(max) = 1W is used in a voltage regulator circuit. If the Zener current varies from 5mA to 60mA, what should be the minimum value of series resistance when the input voltage is 12V?
The temperature coefficient of a Zener diode operating at 6.2V is +2mV/°C. If the ambient temperature increases from 25°C to 75°C, what will be the new Zener voltage?
In a Zener diode voltage regulator circuit, the load current varies from 0 to 50mA. The Zener diode has Vz = 5.1V and requires a minimum current of 2mA to maintain regulation. If Vin = 10V, what should be the series resistance value?
Which of the following statements about the avalanche breakdown mechanism in Zener diodes is most accurate?
A 12V Zener diode has a dynamic resistance of 8Ω at the operating point. If the Zener current changes by 10mA, what will be the change in Zener voltage?
In a temperature compensation circuit using Zener diodes, a 6.8V Zener (temp coeff: +2mV/°C) is connected in series with two forward-biased silicon diodes. What is the overall temperature coefficient of this combination?
What is the primary advantage of using a Zener diode with a breakdown voltage around 6.2V compared to other breakdown voltages?
A Zener diode regulator circuit has the following specifications: Vin = 15V ± 2V, Vout = 9.1V, IL = 20mA to 80mA, Rs = 100Ω. What is the maximum power dissipated by the Zener diode?
Which parameter is most critical when selecting a Zener diode for a precision voltage reference application?
A voltage multiplier circuit uses four 3.3V Zener diodes in series. What is the total regulation voltage and what happens if one Zener diode fails open circuit?
What is the main difference between the I-V characteristics of a Zener diode and a regular PN junction diode in the reverse bias region?
In a Zener diode voltage doubler circuit, two 6.8V Zener diodes are used with appropriate capacitors and diodes. What would be the expected DC output voltage?
A precision 5.1V Zener diode has a voltage tolerance of ±2% and a temperature coefficient of +0.05%/°C. Operating from 0°C to 70°C, what is the total voltage variation range?
Which type of noise is predominantly generated by Zener diodes and becomes significant in low-noise precision applications?
In a switched-mode power supply (SMPS), a 33V Zener diode is used for overvoltage protection. If the normal output is 12V and the Zener triggers at 33V, what is the safety margin and why is this value chosen?
A voltage reference circuit uses a 6.2V Zener diode with a constant current source of 5mA. If the Zener has a dynamic resistance of 2Ω, what will be the output voltage variation for ±0.5mA current variation?
In a Zener diode surge protector circuit for a 5V digital system, what should be the maximum allowable Zener current if the Zener diode has Vz = 6.8V and the system can tolerate up to 6V maximum?
A precision voltage divider uses a 10V Zener diode reference. If the divider consists of two 10kΩ precision resistors (0.1% tolerance), what is the dominant source of error in the 5V output?
In a battery charger circuit, a 14.4V Zener diode is used to prevent overcharging of a 12V lead-acid battery. If the charging current is 2A and suddenly drops to 0.1A, what happens to the Zener diode?
A 3.9V Zener diode has a power dissipation rating of 500mW. What is the maximum allowable current, and what happens if this current is exceeded?
In a crowbar protection circuit, a 15V Zener diode triggers an SCR when the supply voltage exceeds safe limits. If the normal supply is 12V and the Zener has a 10Ω dynamic resistance, what is the trigger sensitivity?
A Zener diode with Vz = 7.5V is used in a differential amplifier circuit for offset voltage compensation. If the amplifier has an input offset of +2mV and the Zener provides -2mV temperature compensation, what is the net offset at 25°C above room temperature?
In a Zener diode clipper circuit, the input is a 20V peak sinusoidal signal. If a 8.2V Zener diode is used, what will be the peak-to-peak voltage of the output signal?
In a Zener diode tester circuit, the forward voltage drop is measured as 0.65V at 10mA. If this same diode shows breakdown at 12V, what can be concluded about the diode?
A 15V Zener diode is connected in series with a 2.2kΩ resistor across a 24V supply. If the Zener current changes from 1mA to 5mA due to temperature variation, what is the effective dynamic resistance?