Unt 1

Question 1

Current

Answer 1

An electric current is a flow of charged particles along conductive wires. Current is represented by the symbol I, and is measured in ampheres, or amps (A)

Question 2

Voltage

Answer 2

Voltage is what causes the current to flow. The cells in a battery provide a push which makes the current flow around the complete circuit. This is represented by the symbol V, and is measured in volts.

Question 3

Resistance

Answer 3

Resistance opposes flow. The resistance, R of a resistor is measured in ohms

Question 4

Resistor

Answer 4

Fixed resistors have a fixed resistance and cannot be changed.
LDR:
Light dependent resistor. The resistance changes depending on how much light falls on it. Very useful for a light sensor.

Question 5

Thermistors

Answer 5

The resistance of a thermistor changes on how hot or cold it is.
This is very useful if you want to make a hear sensor.
Temp rises, resist drops.

Question 6

Transistor

Answer 6

A transistor is an electronic switch. It is triggered a small voltage traveling to the base.

Question 7

Micro switch

Answer 7

Micro switches can be very small usual they include a small arm which pressed clicks. They are very useful and are used in many different machines . It is used as safety switches.

Question 8

Rocker switches

Answer 8

This switch is common may electrical devices. For example, they are found on computer units for turning on and off.

Question 9

Slide switch

Answer 9

Can be stiff to operate amd does not operate smoothly.
Available in a range of sizes.

Question 10

Push switches

Answer 10

These can be pushed to make or push to break.
(Push the switch to make the circuit work)
(Push the switch to break the circuit)

Question 11

Toggle switch

Answer 11

These are available in a miniature and standard size.
The advantage of the toggle switch is that it can be extended and operated by a lever.

Question 12

Reed switch

Answer 12

This is a thin glass contains two thin strips of metal. (The reeds) when a magnet is brought closer together and make contact and the switch is turned on. The switch is turned on. The reeds open again. When the magnet is pulled again.

Question 13

Box pan folder

Answer 13

Bends sheet metal to an angle. Keep your fingers away from the glass.

Question 14

Bending bars, vice and hammer

Answer 14

Bending bars hold the metal in place tightly to allow for a straight line bend.

Question 15

Knock down fittings

Answer 15

What are they used for?
Kitchen cabinets, flat pack furniture.
Knock down fittings are easy to use but are temporary

Question 16

Tensol cement/ liquid solvent cement.

Answer 16

Used to join two pieces of acrylic together, chemically bonds two surfaces together.
Don’t get it on your skin or eyes and use in a well ventilated space.

Question 17

Pop riveting

Answer 17

Riveting is used on metal and plastic.
It is a permanent method of joining.

Common applications:
Ship building, attaching hinges.