8TH GRADE PRACTICE
Physics Problems: Electromagnetic induction, Grade 8
Induction current, Lenz's rule and energy production.
Here the conditions and analysis of the solution can be read without an account. In the simulator, you need to collect the same analyzes yourself: “Given,” formulas, order of steps and answer.
Problem statements
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Problem #67
Electromagnetic induction and Lenz's ruleEvaluate the statement: The appearance of an electric field and induced current when the magnetic flux through a circuit changes.
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Current appears when the magnet moves relative to the coil, the current in an adjacent coil changes, or the circuit rotates.
Answer
Problem #68
Electromagnetic induction and Lenz's ruleEvaluate the statement: The concept “Magnetic flux” means: An induced current is directed in such a way that its magnetic field opposes a change in the magnetic flux.
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The flux changes when the field, area, or orientation of the loop relative to the magnetic induction lines changes.
Answer
Problem #69
Electromagnetic inductionThe north pole of the magnet is brought closer to the coil. What is the direction of the induced current field at the near end of the coil?
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Answer
Problem #70
Generator and transmission of electrical energyEvaluate the statement: Energy is transferred through wires at high voltage to reduce current and heat loss.
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Before the consumer, the voltage is reduced to a safe operating level using transformers.
Answer
Problem #71
Generator and transmission of electrical energyEvaluate the statement: The concept “Electric generator” means: An alternating current device that changes voltage using two coils on a common magnetic circuit.
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Rotation of a coil or magnet periodically changes the flux and creates an alternating voltage.
Answer
Problem #72
Energy transferThe primary winding has 100 turns and is connected to 22 V. The secondary has 1000 turns. Find the secondary voltage of an ideal transformer.
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Answer
The theory behind these problems
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Formulas by topic
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