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 850 primary turns and 5950 secondary turns. If the primary voltage is 40 V, what is the secondary voltage?
40V · 850T · ? V · 5950T
2. An ideal step-up transformer has 950 primary turns and 2850 secondary turns. If the primary voltage is 120 V, what is the secondary voltage?
120V · 950T · ? V · 2850T
3. An ideal step-up transformer has 550 primary turns and 3850 secondary turns. If the primary voltage is 120 V, what is the secondary voltage?
120V · 550T · ? V · 3850T
4. An ideal step-up transformer has 300 primary turns and 1200 secondary turns. If the primary voltage is 90 V, what is the secondary voltage?
90V · 300T · ? V · 1200T
5. An ideal step-up transformer has 750 primary turns and 5250 secondary turns. If the primary voltage is 160 V, what is the secondary voltage?
160V · 750T · ? V · 5250T
6. An ideal step-up transformer has 1500 primary turns and 12000 secondary turns. If the primary voltage is 110 V, what is the secondary voltage?
110V · 1500T · ? V · 12000T
7. An ideal step-up transformer has 800 primary turns and 4000 secondary turns. If the primary voltage is 80 V, what is the secondary voltage?
80V · 800T · ? V · 4000T
8. An ideal step-up transformer has 1100 primary turns and 8800 secondary turns. If the primary voltage is 20 V, what is the secondary voltage?
20V · 1100T · ? V · 8800T
9. An ideal step-up transformer has 1100 primary turns and 2200 secondary turns. If the primary voltage is 120 V, what is the secondary voltage?
120V · 1100T · ? V · 2200T
10. An ideal step-up transformer has 1400 primary turns and 11200 secondary turns. If the primary voltage is 60 V, what is the secondary voltage?
60V · 1400T · ? V · 11200T
11. An ideal step-up transformer has 150 primary turns and 1200 secondary turns. If the primary voltage is 230 V, what is the secondary voltage?
230V · 150T · ? V · 1200T
12. An ideal step-up transformer has 1050 primary turns and 4200 secondary turns. If the primary voltage is 190 V, what is the secondary voltage?
190V · 1050T · ? V · 4200T

12 questions · Seed 45 · 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 850 primary turns and 5950 secondary turns. If the primary voltage is 40 V, what is the secondary voltage?
280 V
Vs = Vp × (Ns ÷ Np) = 40 × (5950 ÷ 850) = 280 V.
2. An ideal step-up transformer has 950 primary turns and 2850 secondary turns. If the primary voltage is 120 V, what is the secondary voltage?
360 V
Vs = Vp × (Ns ÷ Np) = 120 × (2850 ÷ 950) = 360 V.
3. An ideal step-up transformer has 550 primary turns and 3850 secondary turns. If the primary voltage is 120 V, what is the secondary voltage?
840 V
Vs = Vp × (Ns ÷ Np) = 120 × (3850 ÷ 550) = 840 V.
4. An ideal step-up transformer has 300 primary turns and 1200 secondary turns. If the primary voltage is 90 V, what is the secondary voltage?
360 V
Vs = Vp × (Ns ÷ Np) = 90 × (1200 ÷ 300) = 360 V.
5. An ideal step-up transformer has 750 primary turns and 5250 secondary turns. If the primary voltage is 160 V, what is the secondary voltage?
1120 V
Vs = Vp × (Ns ÷ Np) = 160 × (5250 ÷ 750) = 1120 V.
6. An ideal step-up transformer has 1500 primary turns and 12000 secondary turns. If the primary voltage is 110 V, what is the secondary voltage?
880 V
Vs = Vp × (Ns ÷ Np) = 110 × (12000 ÷ 1500) = 880 V.
7. An ideal step-up transformer has 800 primary turns and 4000 secondary turns. If the primary voltage is 80 V, what is the secondary voltage?
400 V
Vs = Vp × (Ns ÷ Np) = 80 × (4000 ÷ 800) = 400 V.
8. An ideal step-up transformer has 1100 primary turns and 8800 secondary turns. If the primary voltage is 20 V, what is the secondary voltage?
160 V
Vs = Vp × (Ns ÷ Np) = 20 × (8800 ÷ 1100) = 160 V.
9. An ideal step-up transformer has 1100 primary turns and 2200 secondary turns. If the primary voltage is 120 V, what is the secondary voltage?
240 V
Vs = Vp × (Ns ÷ Np) = 120 × (2200 ÷ 1100) = 240 V.
10. An ideal step-up transformer has 1400 primary turns and 11200 secondary turns. If the primary voltage is 60 V, what is the secondary voltage?
480 V
Vs = Vp × (Ns ÷ Np) = 60 × (11200 ÷ 1400) = 480 V.
11. An ideal step-up transformer has 150 primary turns and 1200 secondary turns. If the primary voltage is 230 V, what is the secondary voltage?
1840 V
Vs = Vp × (Ns ÷ Np) = 230 × (1200 ÷ 150) = 1840 V.
12. An ideal step-up transformer has 1050 primary turns and 4200 secondary turns. If the primary voltage is 190 V, what is the secondary voltage?
760 V
Vs = Vp × (Ns ÷ Np) = 190 × (4200 ÷ 1050) = 760 V.

12 questions · Seed 45 · 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 850 primary turns and 5950 secondary turns. If the primary voltage is 40 V, what is the secondary voltage?
40V · 850T · ? V · 5950T
2. An ideal step-up transformer has 950 primary turns and 2850 secondary turns. If the primary voltage is 120 V, what is the secondary voltage?
120V · 950T · ? V · 2850T
3. An ideal step-up transformer has 550 primary turns and 3850 secondary turns. If the primary voltage is 120 V, what is the secondary voltage?
120V · 550T · ? V · 3850T
4. An ideal step-up transformer has 300 primary turns and 1200 secondary turns. If the primary voltage is 90 V, what is the secondary voltage?
90V · 300T · ? V · 1200T
5. An ideal step-up transformer has 750 primary turns and 5250 secondary turns. If the primary voltage is 160 V, what is the secondary voltage?
160V · 750T · ? V · 5250T
6. An ideal step-up transformer has 1500 primary turns and 12000 secondary turns. If the primary voltage is 110 V, what is the secondary voltage?
110V · 1500T · ? V · 12000T
7. An ideal step-up transformer has 800 primary turns and 4000 secondary turns. If the primary voltage is 80 V, what is the secondary voltage?
80V · 800T · ? V · 4000T
8. An ideal step-up transformer has 1100 primary turns and 8800 secondary turns. If the primary voltage is 20 V, what is the secondary voltage?
20V · 1100T · ? V · 8800T
9. An ideal step-up transformer has 1100 primary turns and 2200 secondary turns. If the primary voltage is 120 V, what is the secondary voltage?
120V · 1100T · ? V · 2200T
10. An ideal step-up transformer has 1400 primary turns and 11200 secondary turns. If the primary voltage is 60 V, what is the secondary voltage?
60V · 1400T · ? V · 11200T
11. An ideal step-up transformer has 150 primary turns and 1200 secondary turns. If the primary voltage is 230 V, what is the secondary voltage?
230V · 150T · ? V · 1200T
12. An ideal step-up transformer has 1050 primary turns and 4200 secondary turns. If the primary voltage is 190 V, what is the secondary voltage?
190V · 1050T · ? V · 4200T

12 questions · Seed 45 · 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 850 primary turns and 5950 secondary turns. If the primary voltage is 40 V, what is the secondary voltage?
280 V
Vs = Vp × (Ns ÷ Np) = 40 × (5950 ÷ 850) = 280 V.
2. An ideal step-up transformer has 950 primary turns and 2850 secondary turns. If the primary voltage is 120 V, what is the secondary voltage?
360 V
Vs = Vp × (Ns ÷ Np) = 120 × (2850 ÷ 950) = 360 V.
3. An ideal step-up transformer has 550 primary turns and 3850 secondary turns. If the primary voltage is 120 V, what is the secondary voltage?
840 V
Vs = Vp × (Ns ÷ Np) = 120 × (3850 ÷ 550) = 840 V.
4. An ideal step-up transformer has 300 primary turns and 1200 secondary turns. If the primary voltage is 90 V, what is the secondary voltage?
360 V
Vs = Vp × (Ns ÷ Np) = 90 × (1200 ÷ 300) = 360 V.
5. An ideal step-up transformer has 750 primary turns and 5250 secondary turns. If the primary voltage is 160 V, what is the secondary voltage?
1120 V
Vs = Vp × (Ns ÷ Np) = 160 × (5250 ÷ 750) = 1120 V.
6. An ideal step-up transformer has 1500 primary turns and 12000 secondary turns. If the primary voltage is 110 V, what is the secondary voltage?
880 V
Vs = Vp × (Ns ÷ Np) = 110 × (12000 ÷ 1500) = 880 V.
7. An ideal step-up transformer has 800 primary turns and 4000 secondary turns. If the primary voltage is 80 V, what is the secondary voltage?
400 V
Vs = Vp × (Ns ÷ Np) = 80 × (4000 ÷ 800) = 400 V.
8. An ideal step-up transformer has 1100 primary turns and 8800 secondary turns. If the primary voltage is 20 V, what is the secondary voltage?
160 V
Vs = Vp × (Ns ÷ Np) = 20 × (8800 ÷ 1100) = 160 V.
9. An ideal step-up transformer has 1100 primary turns and 2200 secondary turns. If the primary voltage is 120 V, what is the secondary voltage?
240 V
Vs = Vp × (Ns ÷ Np) = 120 × (2200 ÷ 1100) = 240 V.
10. An ideal step-up transformer has 1400 primary turns and 11200 secondary turns. If the primary voltage is 60 V, what is the secondary voltage?
480 V
Vs = Vp × (Ns ÷ Np) = 60 × (11200 ÷ 1400) = 480 V.
11. An ideal step-up transformer has 150 primary turns and 1200 secondary turns. If the primary voltage is 230 V, what is the secondary voltage?
1840 V
Vs = Vp × (Ns ÷ Np) = 230 × (1200 ÷ 150) = 1840 V.
12. An ideal step-up transformer has 1050 primary turns and 4200 secondary turns. If the primary voltage is 190 V, what is the secondary voltage?
760 V
Vs = Vp × (Ns ÷ Np) = 190 × (4200 ÷ 1050) = 760 V.

12 questions · Seed 45 · Age guidance, not curriculum certification