Online Engineering Continuing Education Courses

Introduction to electronic emission, tubes and power supplies

Quiz Questions:

1.	The _____________ is the electron-emitting element of a tube.

		Cathode
		Anode

2.	Diode operation depends upon current flow through the tube.

		True
		False

3.	Factors that limit vacuum tube operation are plate dissipation, maximum average current, maximum peak-plate and current and peak-inverse voltage.

		True
		False

4.	A _________ is basically a diode with a control grid mounted between the plate and the cathode. The control grid gives it the ability to amplify signals.

		Triode
		Diode

5.	Tube biasing is the process of placing a dc voltage, usually negative, on the grid.

		True
		False

6.	The class of operation of an amplifier is not determined by the bias applied to a triode.

		True
		False

7.	_______________is the time required for electrons emitted by the cathode to reach the plate.

		Conducting time
		Transit time

8.	______________were developed to compensate for the effects of inter electrode capacitance.

		Tetrodes
		Cathodes
		Anodes

9.	Pentodes do not suffer from the effects of secondary emission. This is because a negatively charged suppression grid placed between the screen grid and plate forces any electrons emitted back to the plate.

		True
		False

10.	_________ tubes contain a small amount of gas that ionizes and reduces the internal resistance of the tubes.

		Gas filled
		Planar

11.	UHF Tubes are special-purpose tubes designed to operate at ultrahigh frequencies between______________ with minimum effect from transit time limitations.

		100 to 1000 MHz
		200 to 2000 MHz
		300 to 3000 MHz

12.	Figure 3-1 represents ___________________.

		Block diagram of a transformer
		Block diagram of a power supply
		Block diagram of a generating system

13.	Therefore, current or voltage pulses with a value of .318 of the peak value have the same effect on the load as a steady voltage or current.

		True
		False

14.	_________________rectifier circuit uses two diodes (V1 and V2) and a center-tapped transformer (T1).

		Half wave
		Full wave

15.	How many types of filter circuits exist?

		Three
		Four
		Five

16.	What is the most basic type of filter?

		Resistor
		Inductor
		Capacitor

17.	___________ are designed to smooth, or filter, the ripple voltage present on the pulsating dc output of the rectifier.

		Rectifier circuits
		Filter circuits

18.	PI-type filters use both _________ and ____________filters connected in a pi-type configuration.

		Resistive & inductive
		Capacitive & resistive
		Capacitive & inductive

19.	Shunt regulators do not use a variable resistance placed in parallel with the load.

		True
		False

20.	Ballast tube is normally used to control _________ surges.

		Current
		Voltageh