Electricity from Magnetism

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Questions

• The magnetic flux through a coil containing 50 loops changes from 30 Wb to –30 Wb in 0.42 seconds. What is the voltage induced in the coil?
• How does electromagnetic induction work in a large audio speaker?
• How can I construct an electromagnetic brake, whereby the energization of an electromagnet coil would produce mechanical "drag" on a rotating shaft without the need for contact between the shaft and a brake pad?
• If a copper ring is brought closer to the end of a permanent magnet, a repulsive force will develop between the magnet and the ring. The force will cease when the ring stops moving. What is this effect called?
• How many turns of wire must a coil have in order to induce a voltage of 10.5 volts when exposed to a changing magnetic flux with a rate of 0.0075 Wb/s?
• What does the right-hand rule mean?
• What is the Lenz's law?
• Why was the discovery of electromagnetic induction significant?
• What is electromagnetic induction in physics?
• What does electromagnetic induction depend on?
• What are some examples of electromagnetic induction?
• How can I make an electromagnetic induction model?
• How can I make an electromagnetic induction torch?
• How does electromagnetic induction produce electricity?
• How does electromagnetic induction happen?
• How can electromagnetic induction be increased?
• How is electromagnetic induction applied to generators and transformers?
• What is electromagnetic induction in a conductor?
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• A transformer has 150 turns on the primary coil and is connected to a 120 volt power source. How many turns will be needed on the secondary coil to provide a secondary voltage of 40 volts?
• How are transmission lines protected from lightning strikes?
• Can anyone explain Lenz's law with an example?
• What is needed to produce an electromagnet?
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• How do you find the angle in this question?
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• In nuclear physics, what is meant by the term 'mass defect', and what is its relation to nuclear energy?
• How do you determine the height for Part B of this question?
• How is the speed of a wave determined for this question?
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• Why would steel be bad to use as the core of an electromagnet?
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• Can anyone explain this problem with an aid of a diagram?
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• What is a form of electromagnetic induction?
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• At the equator a 1000 turn coil with a cross sectional area of 300 cm2 and a resistance of 15 #Omega# is aligned with its plane perpendicular to the earth’s magnetic field of 7*10^-5 T . If the coil is flipped over how much charge flows through it?