Grade 11 · Science · Physics

11th grade A changing magnetic field makes a current: generators and transformers worksheet

6 printable versionsChallenge Me10 questions · answer keyFree · no account

Level: Building Confidence · On Level · Challenge Me

When it’s done, scan the sheet with your phone and PencilGo marks it and picks the next one. Create a free account

Version

A changing magnetic field makes a current: generators and transformers

Grade 11 Science Worksheet - Challenge Me

NameDate

Circle the best answer, or write your answer on the line.

A line with 2 Ω of resistance carries 6000 W at 240 V. How much power is lost as heat in the line, Ari?
A line with 3 Ω of resistance carries 12000 W at 6000 V. How much power is lost as heat in the line, Bo?
A line with 0.5 Ω of resistance carries 5000 W at 250 V. How much power is lost as heat in the line, Esme?
4.
Why is electrical energy sent along power lines at very high voltage, Jun?
- Higher voltage makes more energy
- Less current, less heat
- High voltage travels faster
5.
What lowers the power-line voltage before it reaches homes, Kira?
- Step-down transformers
- Longer, thinner wires along the way
- Step-up transformers
6.
The same power is sent at 25 times the voltage. How does the heating loss in the line change, Luz?
- It drops to 1/25
- It rises 25 times
- It drops to 1/625
7.
Noah says stepping up voltage with a transformer also steps up the current. Agree or disagree?
- Agree: current and voltage rise together
- Agree: current follows the turns
- Disagree: the current steps down
8.
How does a wireless charging pad charge a phone, Ren?
- It sends charge through the air to the phone
- It heats the battery
- Its changing field induces a current
9.
A magnet falls slowly through a copper tube. Why, Tala?
- Air in the tube holds it up
- Copper is magnetic and grabs it
- Induced currents push back
10.
Which way does an induced current act, Zee?
- With the change, speeding it up
- In no fixed way
- Against the change that caused it

A changing magnetic field makes a current: generators and transformers. Every version has 10 questions, and the answer key prints on the second page.

I can say what makes an induced current: the magnetic field through a coil must change. A faster change or more turns gives a bigger current; reversing the change reverses it.
I can find a transformer's secondary voltage from Vs ÷ Vp = Ns ÷ Np and say whether it steps up or down.
I can use VpIp = VsIs for an ideal transformer: stepping voltage up steps current down, and power out is never more than power in.
I can explain why power lines run at high voltage (smaller current, much smaller I²R heating) and how generators, bike dynamos and wireless chargers use induction.

Standard: HS-PS2-5

induced current: A current made by a changing magnetic field, with no battery

primary coil: The transformer coil the current goes into

secondary coil: The transformer coil the changed current comes out of

step-up / step-down: A transformer that raises / lowers the voltage

alternating current (AC): Current that keeps reversing direction

Your child flipped the ratio. For a transformer, Vs ÷ Vp = Ns ÷ Np, and in an ideal one the current changes the opposite way.

Your child did not square the current. Heating loss in a line is P = I²R.

Your child thought a transformer makes extra energy. It changes voltage and current, but power out can't be more than power in.

What is the most common mistake with a changing magnetic field makes a current: generators and transformers?

Your child flipped the ratio. For a transformer, Vs ÷ Vp = Ns ÷ Np, and in an ideal one the current changes the opposite way.

Are these 11th grade science worksheets free to print?

Yes. All 6 printable versions at each level are free to print, with the answer key, and no account is needed.

Every sheet you scan goes into your child’s record: dated, marked and ready for the year-end portfolio. Homeschool records