A changing magnetic field makes a current: generators and transformers
Grade 11 Science Worksheet - Building Confidence
Circle the best answer, or write your answer on the line.
A transformer's primary coil has 500 turns and gets 120 V. Its secondary coil has 50 turns. What voltage comes out, Ari?
In the diagram, the magnet is held still inside the coil. What does the needle show, Jun?
- Zero
- A steady swing right
- A swing left
In the diagram, the magnet is pulled back out. Which way does the needle swing, Kira?
Use the picture in question 2.
- Right, as before
- It doesn't move
- Left
In the diagram, the magnet is pushed in faster. What happens to the needle's swing, Luz?
Use the picture in question 2.
- It swings farther
- It swings less
- It swings the same
What makes a current flow in a coil with no battery, Milo?
- A changing magnetic field through it
- Warming the coil
- A magnet resting beside it
A coil is moved past a magnet that stays still. Is a current made, Noah?
- No: the magnet must move
- Yes: the field through the coil changes
- No: coils can't make current
A coil with more turns is used with the same moving magnet. What happens to the current, Pia?
- It gets bigger
- It gets smaller
- It stays the same
A transformer has 100 turns on its primary coil and 1000 on its secondary. What kind is it, Ren?
- Neither
- Step-down
- Step-up
A phone charger's transformer has fewer turns on its secondary coil. What does it do to the voltage, Tala?
- Leaves it the same
- Raises it
- Lowers it
Why won't a transformer work with a steady battery current, Zee?
- Transformers need heat
- Batteries are too weak
- The field must keep changing