Lenz’s Law and Conservation of Energy (HSC SSCE Physics): Quizzes
📚Quizzes
Practise the questions
10 questions from this quiz
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Practise the questions
10 questions from this quiz
What does Lenz's Law state about induced currents?
What does Lenz's Law state about induced currents?
They oppose the flux change that caused them
When magnetic flux through a conductor increases, the induced current creates a field in which direction?
When magnetic flux through a conductor increases, the induced current creates a field in which direction?
Opposite to the external field
Why is Lenz's Law essential for energy conservation?
Why is Lenz's Law essential for energy conservation?
Opposition prevents infinite energy creation
What is back emf in a DC motor?
What is back emf in a DC motor?
Induced emf opposing the supplied emf
What happens to motor current when it first starts turning?
What happens to motor current when it first starts turning?
Current is large due to small back emf
Why do many motors use starting resistors?
Why do many motors use starting resistors?
To limit large startup current
What happens when a load is added to a running motor?
What happens when a load is added to a running motor?
Motor slows, back emf drops, current rises
What are eddy currents?
What are eddy currents?
Loops of current induced in conductors
Through which pipe does a magnet fall slowest?
Through which pipe does a magnet fall slowest?
Complete copper pipe
Why does a slit in copper pipe reduce magnetic braking?
Why does a slit in copper pipe reduce magnetic braking?
It prevents complete eddy current loops