Electromagnets


  • Current going through a wire = magnetic field around wire.
  • olenoid
    = long coil of wire. When current runs through it magnetic field is the same as a bar magnet
  • Electromagnets = magnets made from a current – carrying wire
  • Current
    can be turned on and off = magnetic field be turned on and off
    Increase electromagnet strength:

  • More current
  • More turns in solenoid
  • Core of soft iron inside solenoid (steel core would stay magnetised after current turned off)
  • Electric motor made from a loop of coiled wire in a magnetic field
  • Current flows = magnetic field around wire
  • Wire in magnetic field = forces on the loop of wire = forces act in opposite direction = loop of wire turns = motor

 

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


 

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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.

 

 

 

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

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