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Flashcards in Current and Potential Difference Deck (19)
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1

Define 'current'

The flow of electric charge around the circuit

2

When will current only flow across a component?

If there is a potential difference across that component

3

What is the unit for current?

Ampere: A

4

Define 'potential difference'

The driving force that pushes the current around

5

What is the unit for potential difference?

Volts: V

6

Define 'resistance'

Anything in the circuit which slows the flow (of the current) down

7

What is the unit for resistance?

Ohm: Ω

8

The greater the resistance across a component, the ____ the current that flows

(for a given ____ ____ across the component)

The greater the resistance across a component, the smaller the current that flows

(for a given potential difference across the component)

9

Which 2 factors does total charge through a curcuit depend on?

1. Current

2. Time

10

Current is the ____ of ____ of ____

Current is the rate of flow of charge

11

Write the formula triangle for current, total charge, and time

Current = charge / time

12

Current is measured in ____

Amperes (A)

13

Charge is measured in ____

Coulombs (C)

14

Time is measured in ____

Seconds (s)

15

More charge passes around the curcuit when a ____ current flows

More charge passes around the curcuit when a bigger current flows

16

Example:

A battery charger passes a current of 2.5 A through a cell over a period of 4 hours. How much charge does the charger transfer to the cell altogether?

Q = I x t = 2.5 x (4 x 60 x 60) = 36 000 C (36 kC)

17

Potential difference is the ____ ____ per ____ ____ ____

Potential difference is the work done per unit of charge

18

Give the formula for potential difference, work done, and coulombs

P.D. (V) = work done (W) / charge (Q)

19

Potential difference across an electrical component is...

... The amount of energy transferred by that electrical component (e.g. to light and heat energy by a bulb) per unit of charge