Section 7- Electricity And Cicruits

Question 1

What’s the current ?
What’s current measured in?

Answer 1

-flow of electric charge around a Cicruit

-amps

Question 2

What’s potential difference?
What else is potential difference called?
Unit?

Answer 2

-the driving force that pushes the charge around

-voltage

-Volts

Question 3

What’s resistance?
Unit for resistance

Answer 3

-Anything that slows the flow down

• ohm 🧲

Question 4

Why will current flow through an electrical circuit?

Answer 4

• if there’s a potential difference
• if the circuit is closed (complete)

Question 5

What does the current flowing through a component depend on?

Answer 5

Current flowing through a circuit Depends on the POTENTIAL DIFFERENCE and the RESISTANCE of the component

Question 6

What happens to the current when there’s a higher potential difference ?

Answer 6

Higher current

Question 7

Greater resistance = …. Current

Answer 7

Greater resistance = smaller current

Question 8

How do currents move in metals?

Answer 8

-Metals are bonded in a lattice (positive ions surrounded by free electrons)

-these electrons are free to move through the metal

Question 9

Do electrons move from positive—> negative or the other way around ?

Answer 9

Electrons move from positive to negative in a circuit

Question 10

How is charge calculated?

Answer 10

Charge = current X time

Question 11

How do you calculate potential difference using current and resistance ?

Answer 11

Potential difference = current X resistance

Question 12

How do you calculate resistance?

Answer 12

Resistance = p.d /current

Question 13

What does temperature increase along with?

Answer 13

Resistance

Question 14

Why does resistance increase with temperature ?

Answer 14

Electrons collide with ions in the lattice that makes up the reuses or as they flow through it

Gives ions energy —-> causes them to vibrate more

The more the ions vibrate, the harder it is for electrons to get through a resistor as there are more collisions

Question 15

2 types of circuits ..

Answer 15

Series circuits
Parallel circuits

Question 16

What’s a series circuit?

Answer 16

All components are connected in a line

Question 17

3 rules of a series circuit…

Answer 17

-The current is the same everywhere

-total potential difference of the supply is shared between components (pd of each component depends on its resistance)

-total resistance of circuit increases as you add resistors

Question 18

Why are parallel circuits more useful?

Answer 18

If you remove or disconnect one of the parts, it will hardly effect anything at all

Question 19

What happens to the potential difference across all the components in a parallel circuit?

Answer 19

All components get the full source of pd. all their pds will equal the full voltage supply

Question 20

What happens to the current in parallel circuits?

Answer 20

The current is shared between branches

Question 21

What does adding a resistor in a parallel curcuit do to resistance?

Answer 21

Decreases resistance

Question 22

Why does adding a resistor in a parallel curcuit decrease the resistance?

Answer 22

By adding another loop, the current has more than one direction to flow in.

This increases the total current

By using V=IR, an increase in current means a decrease in total resistance for a circuit