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 1600 secondary turns. If the primary voltage is 220 V, what is the secondary voltage?
220V · 400T · ? V · 1600T
2. An ideal step-up transformer has 250 primary turns and 2000 secondary turns. If the primary voltage is 200 V, what is the secondary voltage?
200V · 250T · ? V · 2000T
3. An ideal step-up transformer has 600 primary turns and 4200 secondary turns. If the primary voltage is 160 V, what is the secondary voltage?
160V · 600T · ? V · 4200T
4. An ideal step-up transformer has 750 primary turns and 4500 secondary turns. If the primary voltage is 140 V, what is the secondary voltage?
140V · 750T · ? V · 4500T
5. An ideal step-up transformer has 1300 primary turns and 7800 secondary turns. If the primary voltage is 40 V, what is the secondary voltage?
40V · 1300T · ? V · 7800T
6. An ideal step-up transformer has 750 primary turns and 2250 secondary turns. If the primary voltage is 240 V, what is the secondary voltage?
240V · 750T · ? V · 2250T
7. An ideal step-up transformer has 550 primary turns and 3300 secondary turns. If the primary voltage is 190 V, what is the secondary voltage?
190V · 550T · ? V · 3300T
8. An ideal step-up transformer has 750 primary turns and 6000 secondary turns. If the primary voltage is 210 V, what is the secondary voltage?
210V · 750T · ? V · 6000T
9. An ideal step-up transformer has 300 primary turns and 2100 secondary turns. If the primary voltage is 90 V, what is the secondary voltage?
90V · 300T · ? V · 2100T
10. An ideal step-up transformer has 1100 primary turns and 8800 secondary turns. If the primary voltage is 120 V, what is the secondary voltage?
120V · 1100T · ? V · 8800T
11. An ideal step-up transformer has 1250 primary turns and 7500 secondary turns. If the primary voltage is 190 V, what is the secondary voltage?
190V · 1250T · ? V · 7500T
12. An ideal step-up transformer has 250 primary turns and 750 secondary turns. If the primary voltage is 90 V, what is the secondary voltage?
90V · 250T · ? V · 750T

12 questions · Seed 53 · 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 1600 secondary turns. If the primary voltage is 220 V, what is the secondary voltage?
880 V
Vs = Vp × (Ns ÷ Np) = 220 × (1600 ÷ 400) = 880 V.
2. An ideal step-up transformer has 250 primary turns and 2000 secondary turns. If the primary voltage is 200 V, what is the secondary voltage?
1600 V
Vs = Vp × (Ns ÷ Np) = 200 × (2000 ÷ 250) = 1600 V.
3. An ideal step-up transformer has 600 primary turns and 4200 secondary turns. If the primary voltage is 160 V, what is the secondary voltage?
1120 V
Vs = Vp × (Ns ÷ Np) = 160 × (4200 ÷ 600) = 1120 V.
4. An ideal step-up transformer has 750 primary turns and 4500 secondary turns. If the primary voltage is 140 V, what is the secondary voltage?
840 V
Vs = Vp × (Ns ÷ Np) = 140 × (4500 ÷ 750) = 840 V.
5. An ideal step-up transformer has 1300 primary turns and 7800 secondary turns. If the primary voltage is 40 V, what is the secondary voltage?
240 V
Vs = Vp × (Ns ÷ Np) = 40 × (7800 ÷ 1300) = 240 V.
6. An ideal step-up transformer has 750 primary turns and 2250 secondary turns. If the primary voltage is 240 V, what is the secondary voltage?
720 V
Vs = Vp × (Ns ÷ Np) = 240 × (2250 ÷ 750) = 720 V.
7. An ideal step-up transformer has 550 primary turns and 3300 secondary turns. If the primary voltage is 190 V, what is the secondary voltage?
1140 V
Vs = Vp × (Ns ÷ Np) = 190 × (3300 ÷ 550) = 1140 V.
8. An ideal step-up transformer has 750 primary turns and 6000 secondary turns. If the primary voltage is 210 V, what is the secondary voltage?
1680 V
Vs = Vp × (Ns ÷ Np) = 210 × (6000 ÷ 750) = 1680 V.
9. An ideal step-up transformer has 300 primary turns and 2100 secondary turns. If the primary voltage is 90 V, what is the secondary voltage?
630 V
Vs = Vp × (Ns ÷ Np) = 90 × (2100 ÷ 300) = 630 V.
10. An ideal step-up transformer has 1100 primary turns and 8800 secondary turns. If the primary voltage is 120 V, what is the secondary voltage?
960 V
Vs = Vp × (Ns ÷ Np) = 120 × (8800 ÷ 1100) = 960 V.
11. An ideal step-up transformer has 1250 primary turns and 7500 secondary turns. If the primary voltage is 190 V, what is the secondary voltage?
1140 V
Vs = Vp × (Ns ÷ Np) = 190 × (7500 ÷ 1250) = 1140 V.
12. An ideal step-up transformer has 250 primary turns and 750 secondary turns. If the primary voltage is 90 V, what is the secondary voltage?
270 V
Vs = Vp × (Ns ÷ Np) = 90 × (750 ÷ 250) = 270 V.

12 questions · Seed 53 · 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 1600 secondary turns. If the primary voltage is 220 V, what is the secondary voltage?
220V · 400T · ? V · 1600T
2. An ideal step-up transformer has 250 primary turns and 2000 secondary turns. If the primary voltage is 200 V, what is the secondary voltage?
200V · 250T · ? V · 2000T
3. An ideal step-up transformer has 600 primary turns and 4200 secondary turns. If the primary voltage is 160 V, what is the secondary voltage?
160V · 600T · ? V · 4200T
4. An ideal step-up transformer has 750 primary turns and 4500 secondary turns. If the primary voltage is 140 V, what is the secondary voltage?
140V · 750T · ? V · 4500T
5. An ideal step-up transformer has 1300 primary turns and 7800 secondary turns. If the primary voltage is 40 V, what is the secondary voltage?
40V · 1300T · ? V · 7800T
6. An ideal step-up transformer has 750 primary turns and 2250 secondary turns. If the primary voltage is 240 V, what is the secondary voltage?
240V · 750T · ? V · 2250T
7. An ideal step-up transformer has 550 primary turns and 3300 secondary turns. If the primary voltage is 190 V, what is the secondary voltage?
190V · 550T · ? V · 3300T
8. An ideal step-up transformer has 750 primary turns and 6000 secondary turns. If the primary voltage is 210 V, what is the secondary voltage?
210V · 750T · ? V · 6000T
9. An ideal step-up transformer has 300 primary turns and 2100 secondary turns. If the primary voltage is 90 V, what is the secondary voltage?
90V · 300T · ? V · 2100T
10. An ideal step-up transformer has 1100 primary turns and 8800 secondary turns. If the primary voltage is 120 V, what is the secondary voltage?
120V · 1100T · ? V · 8800T
11. An ideal step-up transformer has 1250 primary turns and 7500 secondary turns. If the primary voltage is 190 V, what is the secondary voltage?
190V · 1250T · ? V · 7500T
12. An ideal step-up transformer has 250 primary turns and 750 secondary turns. If the primary voltage is 90 V, what is the secondary voltage?
90V · 250T · ? V · 750T

12 questions · Seed 53 · 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 1600 secondary turns. If the primary voltage is 220 V, what is the secondary voltage?
880 V
Vs = Vp × (Ns ÷ Np) = 220 × (1600 ÷ 400) = 880 V.
2. An ideal step-up transformer has 250 primary turns and 2000 secondary turns. If the primary voltage is 200 V, what is the secondary voltage?
1600 V
Vs = Vp × (Ns ÷ Np) = 200 × (2000 ÷ 250) = 1600 V.
3. An ideal step-up transformer has 600 primary turns and 4200 secondary turns. If the primary voltage is 160 V, what is the secondary voltage?
1120 V
Vs = Vp × (Ns ÷ Np) = 160 × (4200 ÷ 600) = 1120 V.
4. An ideal step-up transformer has 750 primary turns and 4500 secondary turns. If the primary voltage is 140 V, what is the secondary voltage?
840 V
Vs = Vp × (Ns ÷ Np) = 140 × (4500 ÷ 750) = 840 V.
5. An ideal step-up transformer has 1300 primary turns and 7800 secondary turns. If the primary voltage is 40 V, what is the secondary voltage?
240 V
Vs = Vp × (Ns ÷ Np) = 40 × (7800 ÷ 1300) = 240 V.
6. An ideal step-up transformer has 750 primary turns and 2250 secondary turns. If the primary voltage is 240 V, what is the secondary voltage?
720 V
Vs = Vp × (Ns ÷ Np) = 240 × (2250 ÷ 750) = 720 V.
7. An ideal step-up transformer has 550 primary turns and 3300 secondary turns. If the primary voltage is 190 V, what is the secondary voltage?
1140 V
Vs = Vp × (Ns ÷ Np) = 190 × (3300 ÷ 550) = 1140 V.
8. An ideal step-up transformer has 750 primary turns and 6000 secondary turns. If the primary voltage is 210 V, what is the secondary voltage?
1680 V
Vs = Vp × (Ns ÷ Np) = 210 × (6000 ÷ 750) = 1680 V.
9. An ideal step-up transformer has 300 primary turns and 2100 secondary turns. If the primary voltage is 90 V, what is the secondary voltage?
630 V
Vs = Vp × (Ns ÷ Np) = 90 × (2100 ÷ 300) = 630 V.
10. An ideal step-up transformer has 1100 primary turns and 8800 secondary turns. If the primary voltage is 120 V, what is the secondary voltage?
960 V
Vs = Vp × (Ns ÷ Np) = 120 × (8800 ÷ 1100) = 960 V.
11. An ideal step-up transformer has 1250 primary turns and 7500 secondary turns. If the primary voltage is 190 V, what is the secondary voltage?
1140 V
Vs = Vp × (Ns ÷ Np) = 190 × (7500 ÷ 1250) = 1140 V.
12. An ideal step-up transformer has 250 primary turns and 750 secondary turns. If the primary voltage is 90 V, what is the secondary voltage?
270 V
Vs = Vp × (Ns ÷ Np) = 90 × (750 ÷ 250) = 270 V.

12 questions · Seed 53 · Age guidance, not curriculum certification