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 150 primary turns and 300 secondary turns. If the primary voltage is 30 V, what is the secondary voltage?
30V · 150T · ? V · 300T
2. An ideal step-up transformer has 500 primary turns and 1500 secondary turns. If the primary voltage is 200 V, what is the secondary voltage?
200V · 500T · ? V · 1500T
3. An ideal step-up transformer has 400 primary turns and 1600 secondary turns. If the primary voltage is 80 V, what is the secondary voltage?
80V · 400T · ? V · 1600T
4. An ideal step-up transformer has 700 primary turns and 4900 secondary turns. If the primary voltage is 170 V, what is the secondary voltage?
170V · 700T · ? V · 4900T
5. An ideal step-up transformer has 900 primary turns and 4500 secondary turns. If the primary voltage is 180 V, what is the secondary voltage?
180V · 900T · ? V · 4500T
6. An ideal step-up transformer has 950 primary turns and 2850 secondary turns. If the primary voltage is 70 V, what is the secondary voltage?
70V · 950T · ? V · 2850T
7. An ideal step-up transformer has 1050 primary turns and 7350 secondary turns. If the primary voltage is 80 V, what is the secondary voltage?
80V · 1050T · ? V · 7350T
8. An ideal step-up transformer has 850 primary turns and 3400 secondary turns. If the primary voltage is 30 V, what is the secondary voltage?
30V · 850T · ? V · 3400T
9. An ideal step-up transformer has 1100 primary turns and 5500 secondary turns. If the primary voltage is 160 V, what is the secondary voltage?
160V · 1100T · ? V · 5500T
10. An ideal step-up transformer has 500 primary turns and 4000 secondary turns. If the primary voltage is 20 V, what is the secondary voltage?
20V · 500T · ? V · 4000T
11. An ideal step-up transformer has 700 primary turns and 1400 secondary turns. If the primary voltage is 60 V, what is the secondary voltage?
60V · 700T · ? V · 1400T
12. An ideal step-up transformer has 1100 primary turns and 7700 secondary turns. If the primary voltage is 150 V, what is the secondary voltage?
150V · 1100T · ? V · 7700T

12 questions · Seed 48 · 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 150 primary turns and 300 secondary turns. If the primary voltage is 30 V, what is the secondary voltage?
60 V
Vs = Vp × (Ns ÷ Np) = 30 × (300 ÷ 150) = 60 V.
2. An ideal step-up transformer has 500 primary turns and 1500 secondary turns. If the primary voltage is 200 V, what is the secondary voltage?
600 V
Vs = Vp × (Ns ÷ Np) = 200 × (1500 ÷ 500) = 600 V.
3. An ideal step-up transformer has 400 primary turns and 1600 secondary turns. If the primary voltage is 80 V, what is the secondary voltage?
320 V
Vs = Vp × (Ns ÷ Np) = 80 × (1600 ÷ 400) = 320 V.
4. An ideal step-up transformer has 700 primary turns and 4900 secondary turns. If the primary voltage is 170 V, what is the secondary voltage?
1190 V
Vs = Vp × (Ns ÷ Np) = 170 × (4900 ÷ 700) = 1190 V.
5. An ideal step-up transformer has 900 primary turns and 4500 secondary turns. If the primary voltage is 180 V, what is the secondary voltage?
900 V
Vs = Vp × (Ns ÷ Np) = 180 × (4500 ÷ 900) = 900 V.
6. An ideal step-up transformer has 950 primary turns and 2850 secondary turns. If the primary voltage is 70 V, what is the secondary voltage?
210 V
Vs = Vp × (Ns ÷ Np) = 70 × (2850 ÷ 950) = 210 V.
7. An ideal step-up transformer has 1050 primary turns and 7350 secondary turns. If the primary voltage is 80 V, what is the secondary voltage?
560 V
Vs = Vp × (Ns ÷ Np) = 80 × (7350 ÷ 1050) = 560 V.
8. An ideal step-up transformer has 850 primary turns and 3400 secondary turns. If the primary voltage is 30 V, what is the secondary voltage?
120 V
Vs = Vp × (Ns ÷ Np) = 30 × (3400 ÷ 850) = 120 V.
9. An ideal step-up transformer has 1100 primary turns and 5500 secondary turns. If the primary voltage is 160 V, what is the secondary voltage?
800 V
Vs = Vp × (Ns ÷ Np) = 160 × (5500 ÷ 1100) = 800 V.
10. An ideal step-up transformer has 500 primary turns and 4000 secondary turns. If the primary voltage is 20 V, what is the secondary voltage?
160 V
Vs = Vp × (Ns ÷ Np) = 20 × (4000 ÷ 500) = 160 V.
11. An ideal step-up transformer has 700 primary turns and 1400 secondary turns. If the primary voltage is 60 V, what is the secondary voltage?
120 V
Vs = Vp × (Ns ÷ Np) = 60 × (1400 ÷ 700) = 120 V.
12. An ideal step-up transformer has 1100 primary turns and 7700 secondary turns. If the primary voltage is 150 V, what is the secondary voltage?
1050 V
Vs = Vp × (Ns ÷ Np) = 150 × (7700 ÷ 1100) = 1050 V.

12 questions · Seed 48 · 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 150 primary turns and 300 secondary turns. If the primary voltage is 30 V, what is the secondary voltage?
30V · 150T · ? V · 300T
2. An ideal step-up transformer has 500 primary turns and 1500 secondary turns. If the primary voltage is 200 V, what is the secondary voltage?
200V · 500T · ? V · 1500T
3. An ideal step-up transformer has 400 primary turns and 1600 secondary turns. If the primary voltage is 80 V, what is the secondary voltage?
80V · 400T · ? V · 1600T
4. An ideal step-up transformer has 700 primary turns and 4900 secondary turns. If the primary voltage is 170 V, what is the secondary voltage?
170V · 700T · ? V · 4900T
5. An ideal step-up transformer has 900 primary turns and 4500 secondary turns. If the primary voltage is 180 V, what is the secondary voltage?
180V · 900T · ? V · 4500T
6. An ideal step-up transformer has 950 primary turns and 2850 secondary turns. If the primary voltage is 70 V, what is the secondary voltage?
70V · 950T · ? V · 2850T
7. An ideal step-up transformer has 1050 primary turns and 7350 secondary turns. If the primary voltage is 80 V, what is the secondary voltage?
80V · 1050T · ? V · 7350T
8. An ideal step-up transformer has 850 primary turns and 3400 secondary turns. If the primary voltage is 30 V, what is the secondary voltage?
30V · 850T · ? V · 3400T
9. An ideal step-up transformer has 1100 primary turns and 5500 secondary turns. If the primary voltage is 160 V, what is the secondary voltage?
160V · 1100T · ? V · 5500T
10. An ideal step-up transformer has 500 primary turns and 4000 secondary turns. If the primary voltage is 20 V, what is the secondary voltage?
20V · 500T · ? V · 4000T
11. An ideal step-up transformer has 700 primary turns and 1400 secondary turns. If the primary voltage is 60 V, what is the secondary voltage?
60V · 700T · ? V · 1400T
12. An ideal step-up transformer has 1100 primary turns and 7700 secondary turns. If the primary voltage is 150 V, what is the secondary voltage?
150V · 1100T · ? V · 7700T

12 questions · Seed 48 · 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 150 primary turns and 300 secondary turns. If the primary voltage is 30 V, what is the secondary voltage?
60 V
Vs = Vp × (Ns ÷ Np) = 30 × (300 ÷ 150) = 60 V.
2. An ideal step-up transformer has 500 primary turns and 1500 secondary turns. If the primary voltage is 200 V, what is the secondary voltage?
600 V
Vs = Vp × (Ns ÷ Np) = 200 × (1500 ÷ 500) = 600 V.
3. An ideal step-up transformer has 400 primary turns and 1600 secondary turns. If the primary voltage is 80 V, what is the secondary voltage?
320 V
Vs = Vp × (Ns ÷ Np) = 80 × (1600 ÷ 400) = 320 V.
4. An ideal step-up transformer has 700 primary turns and 4900 secondary turns. If the primary voltage is 170 V, what is the secondary voltage?
1190 V
Vs = Vp × (Ns ÷ Np) = 170 × (4900 ÷ 700) = 1190 V.
5. An ideal step-up transformer has 900 primary turns and 4500 secondary turns. If the primary voltage is 180 V, what is the secondary voltage?
900 V
Vs = Vp × (Ns ÷ Np) = 180 × (4500 ÷ 900) = 900 V.
6. An ideal step-up transformer has 950 primary turns and 2850 secondary turns. If the primary voltage is 70 V, what is the secondary voltage?
210 V
Vs = Vp × (Ns ÷ Np) = 70 × (2850 ÷ 950) = 210 V.
7. An ideal step-up transformer has 1050 primary turns and 7350 secondary turns. If the primary voltage is 80 V, what is the secondary voltage?
560 V
Vs = Vp × (Ns ÷ Np) = 80 × (7350 ÷ 1050) = 560 V.
8. An ideal step-up transformer has 850 primary turns and 3400 secondary turns. If the primary voltage is 30 V, what is the secondary voltage?
120 V
Vs = Vp × (Ns ÷ Np) = 30 × (3400 ÷ 850) = 120 V.
9. An ideal step-up transformer has 1100 primary turns and 5500 secondary turns. If the primary voltage is 160 V, what is the secondary voltage?
800 V
Vs = Vp × (Ns ÷ Np) = 160 × (5500 ÷ 1100) = 800 V.
10. An ideal step-up transformer has 500 primary turns and 4000 secondary turns. If the primary voltage is 20 V, what is the secondary voltage?
160 V
Vs = Vp × (Ns ÷ Np) = 20 × (4000 ÷ 500) = 160 V.
11. An ideal step-up transformer has 700 primary turns and 1400 secondary turns. If the primary voltage is 60 V, what is the secondary voltage?
120 V
Vs = Vp × (Ns ÷ Np) = 60 × (1400 ÷ 700) = 120 V.
12. An ideal step-up transformer has 1100 primary turns and 7700 secondary turns. If the primary voltage is 150 V, what is the secondary voltage?
1050 V
Vs = Vp × (Ns ÷ Np) = 150 × (7700 ÷ 1100) = 1050 V.

12 questions · Seed 48 · Age guidance, not curriculum certification