NCERT Class VIII Science Solutions: Chapter 16-Light Part 5

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LONG ANSWER QUESTIONS

Question 20:

Boojho planned an activity to observe an object A through pipes as shown in Fig, so that he could see objects which he could not directly see.

As showing in fig is a object to be seen

Object to Be Seen

As showing in fig is a object to be seen

  1. How many mirrors should he use to see the objects?

  2. Indicate the positions of the mirrors in the figure.

  3. What must be the angle with respect to the incident light at which he should place the mirrors?

  4. Indicate the direction of rays in the figure.

  5. If any of the mirrors is removed, will he be able to see the objects?

Answer:

  1. Three

  2. As showing in fig is a object to be seen in used lence

    Object to Be Seen in Used Lence

    As showing in fig is a object to be seen in used lence

  3. As showing in fig is a object to be seen in used lence with direction

    Object to Be Seen in Used Lence with Direction

    As showing in fig is a object to be seen in used lence with direction

  4. No, he will not be able to see the objects.

Question 21:

There is a mistake in each of the following ray diagrams given as Fig. a, b, and c. Make the necessary correction (s).

As showing in fig is a mistake in diagram (Q)

Mistake in Diagram (Q)

As showing in fig is a mistake in diagram (Q)

Answer:

The Fig. in all the three cases after correction should be as in the given Fig.

As showing in fig is a mistake in diagram (A)

Mistake in Diagram (A)

As showing in fig is a mistake in diagram (A)

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