IB Physics IA idea · Magnets, fields and induction
IB Physics IA idea: how close to ideal is a real transformer?
The voltage ratio should match the turns ratio, but real cores leak.
These ideas are starting points, not an IA to copy. Never copy an idea blindly: make the question, method and analysis your own, and check your plan with your teacher.
Example research question
How does the secondary voltage of a demountable transformer on a low-voltage AC supply depend on secondary turns from 50 to 600 in eight steps, and how does the efficiency change with load current?
Change the system, the range or the method so the question is yours. Check it against the research question checklist in our Physics IA guide.
Variables
- You change
- secondary turns, 50 to 600 in 8 steps
- You measure
- secondary voltage, 1 to 12 V
- You keep the same
- primary voltage (low-voltage AC, 6 V)
- primary turns
- core
- load
Method
Use a demountable transformer on a low-voltage AC supply and measure RMS voltages with a meter. Add a load and calculate efficiency.
Data analysis
Plot V_s/V_p against N_s/N_p; the gradient shows flux leakage. Measure efficiency against load current and discuss losses.
How it works
You change Secondary turns and measure Secondary voltage (V) in Demountable transformer, keeping Primary turns, Supply voltage, Core arrangement the same. Expect a graph of Secondary voltage V_s / V against Secondary turns N_s: The gradient compared with V_p / N_p shows flux leakage.
Make it yours
Compare core types or air gaps.
Safety
Take care with: mains or high-voltage electricity.
Low-voltage AC only; never connect to mains.
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