1) Give an equation to calculate resistance.

2) Give the meaning and the unit of each symbol.

3) Complete the following table

Resistance (Ω)| Current strength (A)| Potential difference (v)| | 12| 38|

| 0.4| 32|

75| 96| |

36| 15| |

75| | 0.25|

135| | 27|

4) An electric frying pan is connected to a 220V power point. If the current in the element is 12 A, calculate the resistance of the element

5) What will the current strength be if there is a potential difference of 20 V across a wire with a resistance of 5 Ω 6) What potential difference is needed to let a current of 4,5A exist in a 30 Ω resistor 7) Write down the formula you would use to calculate current strength in terms of charge and time. 8) Give the meaning and the unit for each symbol.

9) Complete the following table

Charge| Current| Time|

| 1.2A| 5s|

| 0.4A| 25s|

350C| | 200s|

150C| | 1 minute|

15C| 0.3A| |

0.4C| 8mA| |

10) A current of 0.5A is in an electric circuit. How much Charge flows past a point in the circuit in 20s? 11) What is the current strength through a light bulb if 360C of charge flows through the bulb in 20 min? 12) A current of 4 A moves through a resistor. How long will it take for the charge of 480C to move through it?

13)

14) 4Ω

4Ω

4Ω

1.5 V 14) 1.5V

13.1) What is the total current strength in the above

circuit?

4Ω

4Ω

14.1) What is the current in each branch?

14.2) What is the total current in the circuit

15.)

4.5A

R Ω

3 A

4Ω

15.1) What is the potential difference in the bottom

branch?

15.2) What is the current in the top branch?

15.3) What is the value of the unknown resistor?

16.)

5.| |

| | | | | | | 7.| |

1.| | | 3.| | | | 6.| | | |

| | | | | 1.| | | | | | | | | |

| | | | | | | | | | | |

| | | | | | | | | | | |

2.| 2.| | | | 4.| | | | | | 3.| | | |

| | | | | 4.| | | | | | | | |

| | | | | | | | | |

| | | | |

Across:

1. Measures potential difference

2. A circuit component controlling the flow of

current.

3. The colour of a neutral wire.

4. The unit for resistance.

Down:

1. Circuit components that convert chemical to

electrical energy.

2. A circuit component.

3. Measures current flow.

4. Due to resistance, the wire will become ________.

5. The unit for charge.

6. A circuit arrangement where all the components

are connected one after the other.

7. A circuit arrangement that has different branches.

17) Study the diagram and calculate the following:

(Show all your calculations)

A2=

A3=

V2=

V4=

V5=

R1=

R2=

R3=

Current electricity:

1) R = V / I

2) R = resistance measured in Ω, V = potential difference measured in Volts, I = current strength measured in amperes (A)

3) Complete the following table

Resistance (Ω)| Current strength (A)| Potential difference (v)| 3.2| 12| 38|

80| 0.4| V

32|

75| 96| 7200|

36| 15| R

I

540|

75| 0.003| 0.25|

135| 0.2| 27|

4) R = V / I

= 220 / 12

=18.3 Ω

5) I = V / R

= 20 / 5

= 4 A

6) V = I x R

= 4,5 x 30

=135 V

7) I = Q / t

8) I = current measured in amperes (A), Q = charge measured in coulombs (C), t= time measured in seconds

9) Complete the following table

Charge| Current| Time|

6 C| 1.2A| Q

5s|

10 C| 0.4A| 25s|

350C| 1.75A| 200s|

150C| 2,5A| t

I

1 minute|

15C| 0.3A| 50s|

0.4C| 8mA| 0,4/0.008=50sec|

10) Q = I x t

= 0.5 x 20

=10C

11) I = Q / t

= 360 / 1200

=0.3 A

12) t = Q / I

=480 / 4

=120s = 2min

NOTE: must add in the charge size

13)

13.1)...