ELECTRONICS

1. Has a light dependent resistor (LDR) a greater resistance in the light or in the dark?  

……………….…

2. Write down ONE use for an LDR ………………………………………………………….

3. A negative temperature coefficient thermistor has a low resistance when it is …………….

4. Light emitting diodes make useful replacements for conventional bulbs because they run

at a lower voltage and convert less electrical energy to  ……………….

5. A relay is a device that allows a ………………….. current to be controlled by a  ……………………………one.

6. A logic gate which gives a positive output only if BOTH the inputs are positive is called an

…………… gate.

7. The output from two AND gates are connected to the inputs of an OR gate. If the inputs to one AND gate are both positive and if one of the inputs to the other AND gate is positive and while the other is negative what is the output of the OR gate?  ………………….

8. Write down ONE use for an AND gate ……………………………………………………………

9. The number of free electrons in a semiconductor ……………………… if energy is added to it in the form of light or heat.

10. A current flows through a semiconductor diode in a circuit. If the diode is reversed will the current increase or be reduced to zero?

………………………………………………………………………………………………………….