Magnetic effect of current Worksheet-11
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What constitutes the field of a magnet ?
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What is the advantage of the third wire of earth connection in domestic appliances ?
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How can you show that the magnetic field produced by a given electric current in the wire decreases as the distance from the wire decreases ?
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When is the force experienced by a current-carrying conductor placed in a magnet field the largest ?
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Define the term induced current.
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How is the induced current in a secondary coil related to current in a primary coil ?
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What is meant by the term 'magnetic field' ? Why does a compass needle show deflection when brought near a magnet ?
True / False:
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An electric motor converts mechanical energy into electrical energy.
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An electric generator works on the principle of electromagnetic induction.
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The field at the centre of a long circular coil carrying current will be parallel straight lines.
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A wire with a green insulation is usually the live wire.
Answer:
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The space around a magnet within which its magnetic effect can be experienced constitutes the (magnetic) field of the magnet.
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In case of a defect in any domestic appliance, current leaks. The third wire of earth connection transfers this current to the earth. As a result of this, the user of the appliance is protected from the electric shock.
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If we take a magnetic compass slowly away from the current-carrying conductor, the deflection of the compass decreases. This shows that the magnetic field decreases as we move away from the current-carrying conductor.
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The maximum force is experienced by a current-carrying conductor only when it is perpendicular to the direction of magnetic field in which it is placed.
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The current set up in a closed circuit due to change of magnetic flux in it is called the induced current.
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A changing current in a primary coil sets up an induced current in the secondary coil.
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(i) The space around a magnet in which the force of attraction and repulsion due to the magnet can be detected is called the magnetic field.
(ii) The compass needle shows deflection (when brought near a magnet) due to magnetic force exerted on it by the magnet.
True / False:
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False
Explanation: An electric motor converts electric energy into mechanical energy.
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True
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True
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False
Explanation: wire with a green insulation is usually the earth wire.