diodes

Which of the following impurities could be used to convert intrinsic silicon to extrinsic P type silicon?

• Aluminium.

• Germanium

• Arsenic

• Zinc.

Which of the following values represents a typical junction potential of a silicon diode?

• 0.2V

• 0.6V

• 1.6V

• 3.3V

Which of the following is a common application for Zener diodes.

• Demodulation.

• AC rectification.

• Voltage regulation.

• Input protection.

Which type of transformer is required to create a 180 degree input to a rectifier?

• center-tapped secondary

• step-down secondary

• stepped-up secondary

• split winding primary

The dc current through each diode in a bridge rectifier equals:

• the load current

• half the dc load current

• twice the dc load current

• one-fourth the dc load current

Since diodes are destroyed by excessive current, circuits must have:

• higher voltage sources

• current limiting resistors

• more dopants

• higher current sources

A filtered full-wave rectifier voltage has a smaller ripple than does a half-wave rectifier voltage for the same load resistance and capacitor values because:

• there is a shorter time between peaks

• there is a longer time between peaks

• the larger the ripple, the better the filtering action

• none of the above

Testing a good diode with an ohmmeter should indicate

• high resistance when forward or reverse biased

• low resistance when forward or reverse biased

• high resistance when reverse biased and low resistance when forward biased

• high resistance when forward biased and low resistance when reverse biased

The peak inverse voltage (PIV) across a nonconducting diode in a bridge rectifier equals approximately:

• half the peak secondary voltage

• twice the peak secondary voltage

• the peak value of the secondary voltage

• four times the peak value of the secondary voltage

A pn junction allows current flow when

• the p-type material is more positive than the n-type material

• the n-type material is more positive than the p-type material

• both the n-type and p-type materials have the same potential

• there is no potential on the n-type or p-type materials