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Draw a ray diagram to show the formation of umbra and penumbra both. Label the parts umbra and penumbra in your diagram.
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In the following diagram, draw rays to form umbra on the screen.

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In the following diagram, draw rays to form a penumbra on the screen.

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State the conditions when only the penumbra of an opaque object is obtained on the screen.
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Why is it that the birds flying in the sky do not cast their shadow on the earth?
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Write true or false of the following statement.
Artificial magnets are weaker than the natural magnets.
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Write true or false of the following statement.
Permanent magnets get easily demagnetised.
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Tick the correct answer.
Umbra is a region of
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Fill in the blank.
Temporary magnets are usually made up of .................
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Select the correct answer
Making a magnetic substance a magnet by bringing it closer to another magnet without touching it, is
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Answer the following.
How is a shadow formed? Write the conditions required for a shadow to form.
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Select the correct answer
The artificial magnet used to detect direction in the laboratory is
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What are natural and artificial-magnets?
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Describe the method by which an iron bar can be made a magnet.
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State three differences between the temporary and permanent magnets.
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Name the material of the core of an electromagnet for temporary magnet.
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Tick the most appropriate answer.
Temporary magnets are made of
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Tick the most appropriate answer.
A permanent magnet can be demagnetized by
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Fill in the blank.
Permanent magnets are generally made of steel, cobalt, nickel, or an alloy called ...............
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State if the following statement is true or false. Correct the statement if it is false.
Temporary magnets are made of cobalt.
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