The Physics Question Bank

Ramped Questions for GCSE Physics

GCSE Magnetism

The Motor Effect

Ramped Motor Effect Calculation Questions (F=BIL)

These questions will help you practise using the motor effect equation to calculate force, magnetic flux density, current and length of wire in a magnetic field. Read each question carefully, identify the known values and rearrange the equation when necessary before completing your calculation.

Ramped Motor Effect Calculation Questions (F=BIL)Download

Answers to F=BIL Questions

  1. Force = BIL = 0.5 × 2 × 0.3 = 0.30 N
  2. Force = BIL = 0.4 × 1.5 × 0.08 = 0.048 N
  3. Magnetic flux density = F ÷ (IL) = 0.3 ÷ (5 × 0.12) = 0.50 T
  4. Current = F ÷ (BL) = 1.0 ÷ (0.8 × 0.25) = 5.0 A
  5. Length = F ÷ (BI) = 0.72 ÷ (0.6 × 3) = 0.40 m
  6. Force = BIL = 0.9 × 8 × 0.5 = 3.6 N
  7. Length = F ÷ (BI) = 4.8 ÷ (1.2 × 10) = 0.40 m
  8. Magnetic flux density = F ÷ (IL) = 3 ÷ (15 × 0.4) = 0.50 T
  9. Current = F ÷ (BL) = 6 ÷ (1.5 × 0.2) = 20 A
  10. Force = BIL = 1.4 × 25 × 0.8 = 28 N

Transformers

10 Ramped Questions on How a Transformer Works 


Transformers are used to increase or decrease voltage in electrical circuits and play an important role in the National Grid. These ramped questions will help you build your understanding of how transformers work, from the basic components to explaining energy transfer and efficiency.

10 Ramped Questions on How a Transformer Works!Download

Anwers to How a Transformer works

  1. A transformer is used to change the voltage of an alternating current supply.
  2. The two coils are the primary coil and the secondary coil.
  3. The primary coil is connected to the input voltage supply.
  4. Alternating current (AC) is needed for a transformer to work.
  5. The alternating current produces a changing magnetic field around the primary coil.
  6. An iron core is used because it carries the changing magnetic field efficiently between the coils.
  7. The changing magnetic field in the iron core induces a changing voltage in the secondary coil.
  8. It is a step-down transformer because the secondary coil has fewer turns than the primary coil (100 < 200).
  9. AC flows in the primary coil → a changing magnetic field is produced → the iron core carries the changing magnetic field → the changing magnetic field cuts the secondary coil → a voltage is induced in the secondary coil.
  10. Increasing the voltage reduces the current for the same power, so less energy is wasted as heat in the power lines, making transmission more efficient.

10 Ramped Transformer Calculation Questions using (Vp / Vs = Np / Ns)

These questions will help you practise using the transformer equation to calculate voltages and numbers of turns in a range of real-life situations. Work carefully through each question, making sure you identify the known values and rearrange the equation correctly when needed.

10 Ramped Transformer Calculation Questions using (Vp _ Vs = Np _ Ns)Download

Answers to the above

  1. Ns = 2000 × 12 ÷ 240 = 100 turns
  2. Ns = 1150 × 10 ÷ 230 = 50 turns
  3. Ns = 80 × 100 ÷ 20 = 400 turns
  4. Ns = 5000 × 400000 ÷ 25000 = 80000 turns
  5. Vs = 230 × 50 ÷ 500 = 23 V
  6. Vs = 8 × 900 ÷ 120 = 60 V
  7. Ns = 2300 × 110 ÷ 230 = 1100 turns
  8. Vp = 30 × 1200 ÷ 150 = 240 V
  9. Ns = 400 × 33000 ÷ 800 = 16500 turns
  10. Np = 80 × 240 ÷ 24 = 800 turns

10 Transformer Power Equation Ramped Questions (Vp × Ip = Vs × Is)

These questions will help you practise using the transformer power equation in a range of real-life situations. Start by identifying the values you know, then rearrange the equation if necessary before carrying out your calculation carefully.

10 Transformer Power Equation Ramped Questions (Vp × Ip = Vs × Is)Download

Answers to the above

  1. Is = (240 × 0.2) ÷ 12 = 4 A
  2. Is = (230 × 0.5) ÷ 19 = 6.05 A
  3. Ip = (24 × 5) ÷ 240 = 0.50 A
  4. Vs = (230 × 1.2) ÷ 8 = 34.5 V
  5. Ip = (110 × 20) ÷ 220 = 10 A
  6. Is = (25000 × 500) ÷ 500000 = 25 A
  7. Is = (11000 × 150) ÷ 400000 = 4.125 A
  8. Vp = (48 × 25) ÷ 2 = 600 V
  9. Vs = (800 × 300) ÷ 6 = 40 000 V
  10. Is = (400000 × 120) ÷ 11000 = 4363.6 A ≈ 4364 A

Mixed transformer questions using the turns equation and the power equation – ramped

Transformers change the voltage of an alternating current (AC) supply. The transformer equation links voltage and the number of turns on each coil, while the power equation links voltage and current. In an ideal transformer, power in equals power out, so increasing the voltage decreases the current, and decreasing the voltage increases the current. These questions provide practice using both equations in real-life situations.

10 Mixed Transformer Equation and Power Equation Questions (1)Download

Answers to the above mixed questions

  1. Vs/Vp = Ns/Np, Ns = (5 × 920) ÷ 230 = 20 turns
  2. Vs/Vp = Ns/Np, Vs = (120 × 240) ÷ 600 = 48 V
  3. Power in = Power out, 230 × 0.20 = 12 × Is, Is = 46 ÷ 12 = 3.83 A
  4. Ns = (24 × 1200) ÷ 240 = 120 turns
  5. Power in = Power out, 230 × 0.50 = 23 × Is, Is = 115 ÷ 23 = 5 A
  6. Vp/Vs = Np/Ns = 1500 ÷ 300 = 5, therefore Vs/Vp = 1/5
    Power in = Power out, Ip = (Vs × Is) ÷ Vp = (1 × 4) ÷ 5 = 0.8 A
  7. Ns = (250 × 5000) ÷ 25000 = 50 turns
  8. Power in = Power out, 11000 × 8.0 = 440 × Is, Is = 88000 ÷ 440 = 200 A
  9. a) Vs = (80 × 230) ÷ 2000 = 9.2 V
    b) Power in = Power out, 230 × 1.5 = 9.2 × Is, Is = 345 ÷ 9.2 = 37.5 A
  10. a) Ns = (24 × 1800) ÷ 240 = 180 turns
    b) Power in = Power out, 240 × 2.5 = 24 × Is, Is = 600 ÷ 24 = 25 A
    c) Step-down transformer