TUTORIAL 5.3

1. Diagram 35 shows an electronic symbol representing an electronic component.

• Diode

• Inductor

• Resistor

• Transistor

What is the function of a diode?

• Acts as a current amplifier

• Acts as an automatic switch

• Stores electric charge

• Allows the current to pass in one direction only

Diagram 28 shows a p-n junction diode. When the diode is reverse biased, the depletion layer widens because ...

• The electrons and holes are pulled away from the p-n junction

• The electrons from the n-type are pulled across the p-n junction

• The negative charges flow from the negative terminal to the p-type semiconductor

• The positive charges flow from the positive terminal to the n-type conductor

Diagram 4 shows a full-wave rectifier. Which of the following is the correct path of the current through diodes K, L, M and N and resistor R?

• $L\ \rightarrow\ R\ \rightarrow\ N$

• $M\ \rightarrow\ R\ \rightarrow\ N$

• $K\ \rightarrow\ R\ \rightarrow\ M$

• $N\ \rightarrow\ R\ \rightarrow\ L$

Diagram 6 shows a circuit which has three identical resistors P, Q and R, four diodes and an AC power supply.

Which resistor permitted only direct current (DC) through it?

• P

• R

• Q

• P, Q and R

The function of the capacitor in diagram below is

• Rectifier

• Flows alternating current

• AC and DC filter

• Voltage smoother

The diagram shows a circuit containing bulbs X, Y and Z.

Which bulb in the circuit will light up when the switch is on? (2003)

• Z

• X and Y

• Y and Z

• X,Y and Z

Diagram 2 shows a rectification circuit for an AC current.

When an output resistor is connected to a CRO, the shape of the wave form on the screen is ....

• 
• 
• 
• 

Diagram 5 shows a circuit of four diodes which are connected to batteries and a resistor. Which of the following is the correct path for the current?

• $L\rightarrow M\rightarrow T\rightarrow S\rightarrow U\rightarrow L\rightarrow M\rightarrow N\rightarrow O$

• $L\rightarrow M\rightarrow T\rightarrow R\rightarrow Q\rightarrow O\rightarrow N\rightarrow M\rightarrow L$

• $L\rightarrow M\rightarrow T\rightarrow R\rightarrow Q\rightarrow O\rightarrow N\rightarrow S\rightarrow U$

• $U\rightarrow S\rightarrow T\rightarrow R\rightarrow Q\rightarrow O\rightarrow N\rightarrow M\rightarrow L$

Diagram 27 shows a full wave rectifier circuit.

The output of the wave form smoothen because...

• The resistance of the resistor is always increasing and decreasing

• The charges in the capacitor is always increasing and decreasing

• The number of electrons in the CRO is always increasing and decreasing

• The current flows through the diode is always increasing and decreasing