Electricity

Question 1

State an advantage each of using a series and parallel circuit

Answer 1

Series: Cheaper/Easier to make
Parallel: Current will still flow even if there is a break in the circuit as there is another path for it to take.

Question 2

What are the two missing words?

Frequency is the number of times that the Ac changes ____________.

The Dc direction is ____________.

Answer 2

Direction
Continuos

Question 3

If the resistance is high what will the current be ?

Answer 3

Low

Question 4

State the equations for Resistance in series and the Voltage .

Answer 4

Resistance : Rt=R1+R2…
Voltage: Vt=V1=V2

Question 5

True or False?
When calculating the total resistance in parallel it will always be less than the smallest resistance given from a component .

Answer 5

True

Question 6

What would u do to get the total resistance in parallel from this?
1/Rt= 9/81

Answer 6

Flip it on both sides so that is becomes Rt/1= 81/9 and get ur answer or 9 ohms

Question 7

State three facts abt capacitors

Answer 7

• Store Charge ie Electrical Energy
• Take time to charge/discharge
  -When fully charged, they will have the same voltage as the supply

Question 8

State two components that can alter their resistance based on their external conditions?

Answer 8

LDR = LIGHT DEPENDANT Diode
Thermistor = Temperature

Question 9

What two acronyms help remember how Thermistors and LDRs work?

Answer 9

Turd- Temperature Up Resistance Down
Lurd- Light Up Resistance Down

Question 10

Why are LEDs more efficient than Filament Lamps and why must resistors be placed in series w them?

Answer 10

They are more effective as they don’t heat up during us and resistors must be placed in series as they get damaged by high currents.

Question 11

What energy conversion takes place in an LED ?

Answer 11

Electrical Energy—> Light Energy

Question 12

Potential Diver Circuits
a) What are the two equations used in this topic?
b) Which one is needed it u are not given the Supply Voltage?

Answer 12

a) V2= (R1/R1+R2)×Vs
V1/V2=R1/R2
b) V1/V2=P1/P2

Question 13

Give the definition for Electrical Power

Answer 13

Electrical energy transferred per second

Question 14

What are the two types of transistors, and what Voltage will they switch on at ?

Answer 14

Mosfet:2V
NPN:0.7V

Question 15

Explain how a fuse works to protect the wires in a plug

Answer 15

A fuse contains a thin wire that will break (melt) when two large of a current flows through an appliance.

Question 16

Which fuse will each appliance need?
A. Has a wattage of 812
B. Has a wattage or 400

Answer 16

A: 13A fuse
B: 3A fuse