ScienceAges 13-15

Transformer turns & voltage ratio

Use the ideal transformer ratio Vs ÷ Vp = Ns ÷ Np to calculate secondary output voltage. Review suitability for your learners before teaching.

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Worksheet StudioPractice pack · Ages 13-15

Transformer turns & voltage ratio

Take your time. Show your thinking.

1. An ideal step-up transformer has 400 primary turns and 2800 secondary turns. If the primary voltage is 190 V, what is the secondary voltage?
190V · 400T · ? V · 2800T
2. An ideal step-up transformer has 850 primary turns and 5950 secondary turns. If the primary voltage is 70 V, what is the secondary voltage?
70V · 850T · ? V · 5950T
3. An ideal step-up transformer has 250 primary turns and 500 secondary turns. If the primary voltage is 210 V, what is the secondary voltage?
210V · 250T · ? V · 500T
4. An ideal step-up transformer has 300 primary turns and 2100 secondary turns. If the primary voltage is 110 V, what is the secondary voltage?
110V · 300T · ? V · 2100T
5. An ideal step-up transformer has 800 primary turns and 4800 secondary turns. If the primary voltage is 120 V, what is the secondary voltage?
120V · 800T · ? V · 4800T
6. An ideal step-up transformer has 450 primary turns and 2250 secondary turns. If the primary voltage is 200 V, what is the secondary voltage?
200V · 450T · ? V · 2250T
7. An ideal step-up transformer has 1400 primary turns and 7000 secondary turns. If the primary voltage is 170 V, what is the secondary voltage?
170V · 1400T · ? V · 7000T
8. An ideal step-up transformer has 300 primary turns and 2100 secondary turns. If the primary voltage is 240 V, what is the secondary voltage?
240V · 300T · ? V · 2100T
9. An ideal step-up transformer has 900 primary turns and 1800 secondary turns. If the primary voltage is 200 V, what is the secondary voltage?
200V · 900T · ? V · 1800T
10. An ideal step-up transformer has 300 primary turns and 2100 secondary turns. If the primary voltage is 20 V, what is the secondary voltage?
20V · 300T · ? V · 2100T
11. An ideal step-up transformer has 1050 primary turns and 3150 secondary turns. If the primary voltage is 230 V, what is the secondary voltage?
230V · 1050T · ? V · 3150T
12. An ideal step-up transformer has 400 primary turns and 1600 secondary turns. If the primary voltage is 140 V, what is the secondary voltage?
140V · 400T · ? V · 1600T

12 questions · Seed 49 · Age guidance, not curriculum certification

View the answer key

Worksheet StudioAnswer key · Ages 13-15

Transformer turns & voltage ratio

Answers and reasoning. Review before teaching.

1. An ideal step-up transformer has 400 primary turns and 2800 secondary turns. If the primary voltage is 190 V, what is the secondary voltage?
1330 V
Vs = Vp × (Ns ÷ Np) = 190 × (2800 ÷ 400) = 1330 V.
2. An ideal step-up transformer has 850 primary turns and 5950 secondary turns. If the primary voltage is 70 V, what is the secondary voltage?
490 V
Vs = Vp × (Ns ÷ Np) = 70 × (5950 ÷ 850) = 490 V.
3. An ideal step-up transformer has 250 primary turns and 500 secondary turns. If the primary voltage is 210 V, what is the secondary voltage?
420 V
Vs = Vp × (Ns ÷ Np) = 210 × (500 ÷ 250) = 420 V.
4. An ideal step-up transformer has 300 primary turns and 2100 secondary turns. If the primary voltage is 110 V, what is the secondary voltage?
770 V
Vs = Vp × (Ns ÷ Np) = 110 × (2100 ÷ 300) = 770 V.
5. An ideal step-up transformer has 800 primary turns and 4800 secondary turns. If the primary voltage is 120 V, what is the secondary voltage?
720 V
Vs = Vp × (Ns ÷ Np) = 120 × (4800 ÷ 800) = 720 V.
6. An ideal step-up transformer has 450 primary turns and 2250 secondary turns. If the primary voltage is 200 V, what is the secondary voltage?
1000 V
Vs = Vp × (Ns ÷ Np) = 200 × (2250 ÷ 450) = 1000 V.
7. An ideal step-up transformer has 1400 primary turns and 7000 secondary turns. If the primary voltage is 170 V, what is the secondary voltage?
850 V
Vs = Vp × (Ns ÷ Np) = 170 × (7000 ÷ 1400) = 850 V.
8. An ideal step-up transformer has 300 primary turns and 2100 secondary turns. If the primary voltage is 240 V, what is the secondary voltage?
1680 V
Vs = Vp × (Ns ÷ Np) = 240 × (2100 ÷ 300) = 1680 V.
9. An ideal step-up transformer has 900 primary turns and 1800 secondary turns. If the primary voltage is 200 V, what is the secondary voltage?
400 V
Vs = Vp × (Ns ÷ Np) = 200 × (1800 ÷ 900) = 400 V.
10. An ideal step-up transformer has 300 primary turns and 2100 secondary turns. If the primary voltage is 20 V, what is the secondary voltage?
140 V
Vs = Vp × (Ns ÷ Np) = 20 × (2100 ÷ 300) = 140 V.
11. An ideal step-up transformer has 1050 primary turns and 3150 secondary turns. If the primary voltage is 230 V, what is the secondary voltage?
690 V
Vs = Vp × (Ns ÷ Np) = 230 × (3150 ÷ 1050) = 690 V.
12. An ideal step-up transformer has 400 primary turns and 1600 secondary turns. If the primary voltage is 140 V, what is the secondary voltage?
560 V
Vs = Vp × (Ns ÷ Np) = 140 × (1600 ÷ 400) = 560 V.

12 questions · Seed 49 · Age guidance, not curriculum certification

Worksheet StudioPractice pack · Ages 13-15

Transformer turns & voltage ratio

Take your time. Show your thinking.

1. An ideal step-up transformer has 400 primary turns and 2800 secondary turns. If the primary voltage is 190 V, what is the secondary voltage?
190V · 400T · ? V · 2800T
2. An ideal step-up transformer has 850 primary turns and 5950 secondary turns. If the primary voltage is 70 V, what is the secondary voltage?
70V · 850T · ? V · 5950T
3. An ideal step-up transformer has 250 primary turns and 500 secondary turns. If the primary voltage is 210 V, what is the secondary voltage?
210V · 250T · ? V · 500T
4. An ideal step-up transformer has 300 primary turns and 2100 secondary turns. If the primary voltage is 110 V, what is the secondary voltage?
110V · 300T · ? V · 2100T
5. An ideal step-up transformer has 800 primary turns and 4800 secondary turns. If the primary voltage is 120 V, what is the secondary voltage?
120V · 800T · ? V · 4800T
6. An ideal step-up transformer has 450 primary turns and 2250 secondary turns. If the primary voltage is 200 V, what is the secondary voltage?
200V · 450T · ? V · 2250T
7. An ideal step-up transformer has 1400 primary turns and 7000 secondary turns. If the primary voltage is 170 V, what is the secondary voltage?
170V · 1400T · ? V · 7000T
8. An ideal step-up transformer has 300 primary turns and 2100 secondary turns. If the primary voltage is 240 V, what is the secondary voltage?
240V · 300T · ? V · 2100T
9. An ideal step-up transformer has 900 primary turns and 1800 secondary turns. If the primary voltage is 200 V, what is the secondary voltage?
200V · 900T · ? V · 1800T
10. An ideal step-up transformer has 300 primary turns and 2100 secondary turns. If the primary voltage is 20 V, what is the secondary voltage?
20V · 300T · ? V · 2100T
11. An ideal step-up transformer has 1050 primary turns and 3150 secondary turns. If the primary voltage is 230 V, what is the secondary voltage?
230V · 1050T · ? V · 3150T
12. An ideal step-up transformer has 400 primary turns and 1600 secondary turns. If the primary voltage is 140 V, what is the secondary voltage?
140V · 400T · ? V · 1600T

12 questions · Seed 49 · Age guidance, not curriculum certification

Worksheet StudioAnswer key · Ages 13-15

Transformer turns & voltage ratio

Answers and reasoning. Review before teaching.

1. An ideal step-up transformer has 400 primary turns and 2800 secondary turns. If the primary voltage is 190 V, what is the secondary voltage?
1330 V
Vs = Vp × (Ns ÷ Np) = 190 × (2800 ÷ 400) = 1330 V.
2. An ideal step-up transformer has 850 primary turns and 5950 secondary turns. If the primary voltage is 70 V, what is the secondary voltage?
490 V
Vs = Vp × (Ns ÷ Np) = 70 × (5950 ÷ 850) = 490 V.
3. An ideal step-up transformer has 250 primary turns and 500 secondary turns. If the primary voltage is 210 V, what is the secondary voltage?
420 V
Vs = Vp × (Ns ÷ Np) = 210 × (500 ÷ 250) = 420 V.
4. An ideal step-up transformer has 300 primary turns and 2100 secondary turns. If the primary voltage is 110 V, what is the secondary voltage?
770 V
Vs = Vp × (Ns ÷ Np) = 110 × (2100 ÷ 300) = 770 V.
5. An ideal step-up transformer has 800 primary turns and 4800 secondary turns. If the primary voltage is 120 V, what is the secondary voltage?
720 V
Vs = Vp × (Ns ÷ Np) = 120 × (4800 ÷ 800) = 720 V.
6. An ideal step-up transformer has 450 primary turns and 2250 secondary turns. If the primary voltage is 200 V, what is the secondary voltage?
1000 V
Vs = Vp × (Ns ÷ Np) = 200 × (2250 ÷ 450) = 1000 V.
7. An ideal step-up transformer has 1400 primary turns and 7000 secondary turns. If the primary voltage is 170 V, what is the secondary voltage?
850 V
Vs = Vp × (Ns ÷ Np) = 170 × (7000 ÷ 1400) = 850 V.
8. An ideal step-up transformer has 300 primary turns and 2100 secondary turns. If the primary voltage is 240 V, what is the secondary voltage?
1680 V
Vs = Vp × (Ns ÷ Np) = 240 × (2100 ÷ 300) = 1680 V.
9. An ideal step-up transformer has 900 primary turns and 1800 secondary turns. If the primary voltage is 200 V, what is the secondary voltage?
400 V
Vs = Vp × (Ns ÷ Np) = 200 × (1800 ÷ 900) = 400 V.
10. An ideal step-up transformer has 300 primary turns and 2100 secondary turns. If the primary voltage is 20 V, what is the secondary voltage?
140 V
Vs = Vp × (Ns ÷ Np) = 20 × (2100 ÷ 300) = 140 V.
11. An ideal step-up transformer has 1050 primary turns and 3150 secondary turns. If the primary voltage is 230 V, what is the secondary voltage?
690 V
Vs = Vp × (Ns ÷ Np) = 230 × (3150 ÷ 1050) = 690 V.
12. An ideal step-up transformer has 400 primary turns and 1600 secondary turns. If the primary voltage is 140 V, what is the secondary voltage?
560 V
Vs = Vp × (Ns ÷ Np) = 140 × (1600 ÷ 400) = 560 V.

12 questions · Seed 49 · Age guidance, not curriculum certification