Select Page

Electric Fields

• Electric field is created around any electrically charged object
• Closer to the object you get = stronger the field is
• You can show electric fields around an object by drawing field lines.
• Electric field lines always go from positive to negative
• Always at right angles to the surface
• Closer together the lines = stronger field
• Charged object placed in an electric field of another object = feels force = causes the attraction or repulsion
• Force is caused by the electric fields of each charged objects interacting with each other
• Force on an object links to the strength of the electric field it is in. Increase the distance between the charged objects = strength of the field decreases and force between them gets smaller
• Sparks are caused when there is a high potential difference between a charged object and the earth
• High potential difference = strong electric field between the charged object and the earthed object = causes electrons in the air particles to be removed (known as ionization )
• Air is usually an insulator but when it is ionized it is more conductive, allowing a current to flow through it = a spark

How long have you…? (present perfect 4) Exercises

Use the information given to create questions beginning with ‘How long…?’

• It is snowing.

• The weather is shining.

• John and Kate are married.

• My brother has gone on holiday.

• My aunty and uncle live in Canada.

• My sister is a teacher.

• I work at the chemist.

• I’ve known Susan since I was a baby.

• Jonathan is learning to speak to Mandarin.

Fill in the missing gaps in the sentences using the present perfect (=has/have + past participle)

• I have known Kate a long time.

• My brother has been playing the piano he was 11 years old.

• My mum and dad on holiday to America. They

gone since last Sunday.

• I Ben and Emma since primary school.

We to the same primary and secondary school.

• My sister learning to speak French because she
is going to France next month.

Use the appropriate words in the missing gaps.

have you lived       lives      to

has been       works        have known

I have bought       have worked.

• My sister in Spain. She is studying Spanish

with her friend Rosie. I Rosie since I was 5.

• Spencer like with Jamie. They have worked

together for 2 years.

• How long in Australia?

• a new dress for prom.

• He to Thorpe park.

Challenge: Create 4 of your own questions beginning with ‘How long……?’

1.

2.

3.

4.

1 2 3 4 5 6

“Every accomplishment starts
With the decision to try.” Gail Dever

++44 (0)1924 506010