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 1150 primary turns and 2300 secondary turns. If the primary voltage is 40 V, what is the secondary voltage?
40V · 1150T · ? V · 2300T
2. An ideal step-up transformer has 150 primary turns and 1200 secondary turns. If the primary voltage is 160 V, what is the secondary voltage?
160V · 150T · ? V · 1200T
3. An ideal step-up transformer has 1300 primary turns and 3900 secondary turns. If the primary voltage is 130 V, what is the secondary voltage?
130V · 1300T · ? V · 3900T
4. An ideal step-up transformer has 1400 primary turns and 2800 secondary turns. If the primary voltage is 210 V, what is the secondary voltage?
210V · 1400T · ? V · 2800T
5. An ideal step-up transformer has 1450 primary turns and 4350 secondary turns. If the primary voltage is 200 V, what is the secondary voltage?
200V · 1450T · ? V · 4350T
6. An ideal step-up transformer has 950 primary turns and 1900 secondary turns. If the primary voltage is 20 V, what is the secondary voltage?
20V · 950T · ? V · 1900T
7. An ideal step-up transformer has 300 primary turns and 2100 secondary turns. If the primary voltage is 30 V, what is the secondary voltage?
30V · 300T · ? V · 2100T
8. An ideal step-up transformer has 850 primary turns and 3400 secondary turns. If the primary voltage is 230 V, what is the secondary voltage?
230V · 850T · ? V · 3400T
9. An ideal step-up transformer has 550 primary turns and 2750 secondary turns. If the primary voltage is 40 V, what is the secondary voltage?
40V · 550T · ? V · 2750T
10. An ideal step-up transformer has 1100 primary turns and 2200 secondary turns. If the primary voltage is 220 V, what is the secondary voltage?
220V · 1100T · ? V · 2200T
11. An ideal step-up transformer has 1250 primary turns and 5000 secondary turns. If the primary voltage is 160 V, what is the secondary voltage?
160V · 1250T · ? V · 5000T
12. An ideal step-up transformer has 500 primary turns and 4000 secondary turns. If the primary voltage is 60 V, what is the secondary voltage?
60V · 500T · ? V · 4000T

12 questions · Seed 54 · 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 1150 primary turns and 2300 secondary turns. If the primary voltage is 40 V, what is the secondary voltage?
80 V
Vs = Vp × (Ns ÷ Np) = 40 × (2300 ÷ 1150) = 80 V.
2. An ideal step-up transformer has 150 primary turns and 1200 secondary turns. If the primary voltage is 160 V, what is the secondary voltage?
1280 V
Vs = Vp × (Ns ÷ Np) = 160 × (1200 ÷ 150) = 1280 V.
3. An ideal step-up transformer has 1300 primary turns and 3900 secondary turns. If the primary voltage is 130 V, what is the secondary voltage?
390 V
Vs = Vp × (Ns ÷ Np) = 130 × (3900 ÷ 1300) = 390 V.
4. An ideal step-up transformer has 1400 primary turns and 2800 secondary turns. If the primary voltage is 210 V, what is the secondary voltage?
420 V
Vs = Vp × (Ns ÷ Np) = 210 × (2800 ÷ 1400) = 420 V.
5. An ideal step-up transformer has 1450 primary turns and 4350 secondary turns. If the primary voltage is 200 V, what is the secondary voltage?
600 V
Vs = Vp × (Ns ÷ Np) = 200 × (4350 ÷ 1450) = 600 V.
6. An ideal step-up transformer has 950 primary turns and 1900 secondary turns. If the primary voltage is 20 V, what is the secondary voltage?
40 V
Vs = Vp × (Ns ÷ Np) = 20 × (1900 ÷ 950) = 40 V.
7. An ideal step-up transformer has 300 primary turns and 2100 secondary turns. If the primary voltage is 30 V, what is the secondary voltage?
210 V
Vs = Vp × (Ns ÷ Np) = 30 × (2100 ÷ 300) = 210 V.
8. An ideal step-up transformer has 850 primary turns and 3400 secondary turns. If the primary voltage is 230 V, what is the secondary voltage?
920 V
Vs = Vp × (Ns ÷ Np) = 230 × (3400 ÷ 850) = 920 V.
9. An ideal step-up transformer has 550 primary turns and 2750 secondary turns. If the primary voltage is 40 V, what is the secondary voltage?
200 V
Vs = Vp × (Ns ÷ Np) = 40 × (2750 ÷ 550) = 200 V.
10. An ideal step-up transformer has 1100 primary turns and 2200 secondary turns. If the primary voltage is 220 V, what is the secondary voltage?
440 V
Vs = Vp × (Ns ÷ Np) = 220 × (2200 ÷ 1100) = 440 V.
11. An ideal step-up transformer has 1250 primary turns and 5000 secondary turns. If the primary voltage is 160 V, what is the secondary voltage?
640 V
Vs = Vp × (Ns ÷ Np) = 160 × (5000 ÷ 1250) = 640 V.
12. An ideal step-up transformer has 500 primary turns and 4000 secondary turns. If the primary voltage is 60 V, what is the secondary voltage?
480 V
Vs = Vp × (Ns ÷ Np) = 60 × (4000 ÷ 500) = 480 V.

12 questions · Seed 54 · 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 1150 primary turns and 2300 secondary turns. If the primary voltage is 40 V, what is the secondary voltage?
40V · 1150T · ? V · 2300T
2. An ideal step-up transformer has 150 primary turns and 1200 secondary turns. If the primary voltage is 160 V, what is the secondary voltage?
160V · 150T · ? V · 1200T
3. An ideal step-up transformer has 1300 primary turns and 3900 secondary turns. If the primary voltage is 130 V, what is the secondary voltage?
130V · 1300T · ? V · 3900T
4. An ideal step-up transformer has 1400 primary turns and 2800 secondary turns. If the primary voltage is 210 V, what is the secondary voltage?
210V · 1400T · ? V · 2800T
5. An ideal step-up transformer has 1450 primary turns and 4350 secondary turns. If the primary voltage is 200 V, what is the secondary voltage?
200V · 1450T · ? V · 4350T
6. An ideal step-up transformer has 950 primary turns and 1900 secondary turns. If the primary voltage is 20 V, what is the secondary voltage?
20V · 950T · ? V · 1900T
7. An ideal step-up transformer has 300 primary turns and 2100 secondary turns. If the primary voltage is 30 V, what is the secondary voltage?
30V · 300T · ? V · 2100T
8. An ideal step-up transformer has 850 primary turns and 3400 secondary turns. If the primary voltage is 230 V, what is the secondary voltage?
230V · 850T · ? V · 3400T
9. An ideal step-up transformer has 550 primary turns and 2750 secondary turns. If the primary voltage is 40 V, what is the secondary voltage?
40V · 550T · ? V · 2750T
10. An ideal step-up transformer has 1100 primary turns and 2200 secondary turns. If the primary voltage is 220 V, what is the secondary voltage?
220V · 1100T · ? V · 2200T
11. An ideal step-up transformer has 1250 primary turns and 5000 secondary turns. If the primary voltage is 160 V, what is the secondary voltage?
160V · 1250T · ? V · 5000T
12. An ideal step-up transformer has 500 primary turns and 4000 secondary turns. If the primary voltage is 60 V, what is the secondary voltage?
60V · 500T · ? V · 4000T

12 questions · Seed 54 · 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 1150 primary turns and 2300 secondary turns. If the primary voltage is 40 V, what is the secondary voltage?
80 V
Vs = Vp × (Ns ÷ Np) = 40 × (2300 ÷ 1150) = 80 V.
2. An ideal step-up transformer has 150 primary turns and 1200 secondary turns. If the primary voltage is 160 V, what is the secondary voltage?
1280 V
Vs = Vp × (Ns ÷ Np) = 160 × (1200 ÷ 150) = 1280 V.
3. An ideal step-up transformer has 1300 primary turns and 3900 secondary turns. If the primary voltage is 130 V, what is the secondary voltage?
390 V
Vs = Vp × (Ns ÷ Np) = 130 × (3900 ÷ 1300) = 390 V.
4. An ideal step-up transformer has 1400 primary turns and 2800 secondary turns. If the primary voltage is 210 V, what is the secondary voltage?
420 V
Vs = Vp × (Ns ÷ Np) = 210 × (2800 ÷ 1400) = 420 V.
5. An ideal step-up transformer has 1450 primary turns and 4350 secondary turns. If the primary voltage is 200 V, what is the secondary voltage?
600 V
Vs = Vp × (Ns ÷ Np) = 200 × (4350 ÷ 1450) = 600 V.
6. An ideal step-up transformer has 950 primary turns and 1900 secondary turns. If the primary voltage is 20 V, what is the secondary voltage?
40 V
Vs = Vp × (Ns ÷ Np) = 20 × (1900 ÷ 950) = 40 V.
7. An ideal step-up transformer has 300 primary turns and 2100 secondary turns. If the primary voltage is 30 V, what is the secondary voltage?
210 V
Vs = Vp × (Ns ÷ Np) = 30 × (2100 ÷ 300) = 210 V.
8. An ideal step-up transformer has 850 primary turns and 3400 secondary turns. If the primary voltage is 230 V, what is the secondary voltage?
920 V
Vs = Vp × (Ns ÷ Np) = 230 × (3400 ÷ 850) = 920 V.
9. An ideal step-up transformer has 550 primary turns and 2750 secondary turns. If the primary voltage is 40 V, what is the secondary voltage?
200 V
Vs = Vp × (Ns ÷ Np) = 40 × (2750 ÷ 550) = 200 V.
10. An ideal step-up transformer has 1100 primary turns and 2200 secondary turns. If the primary voltage is 220 V, what is the secondary voltage?
440 V
Vs = Vp × (Ns ÷ Np) = 220 × (2200 ÷ 1100) = 440 V.
11. An ideal step-up transformer has 1250 primary turns and 5000 secondary turns. If the primary voltage is 160 V, what is the secondary voltage?
640 V
Vs = Vp × (Ns ÷ Np) = 160 × (5000 ÷ 1250) = 640 V.
12. An ideal step-up transformer has 500 primary turns and 4000 secondary turns. If the primary voltage is 60 V, what is the secondary voltage?
480 V
Vs = Vp × (Ns ÷ Np) = 60 × (4000 ÷ 500) = 480 V.

12 questions · Seed 54 · Age guidance, not curriculum certification