1.
[1]What is
the far point and near point of the human eye with normal vision?
2.
[1]The far
point of a myopic person is 80 cm in front of the eye. What is the nature and power
of the lens required to correct the problem
3.
[1]Why is a
normal eye not able to see clearly the objects placed closer than 25 cm?
4.
[1]What is
the function of Ciliary muscle ?
5.
[1]How is
the amount of light controlled in the human eye ?
6.
[1]What is
the role of Cornea in human eye?
7.
[1]How we
are able to see in the dark room after some time ?
8.
[1]The
focal length of a concave lens is 50 cm. Its power is
9.
[2]why the
planets do not twinkle?
10.
[3]Draw a
schematic diagram of human eye and label it
11.
[5]A
student finds the writing on the blackboard as blurred and unclear when sitting
on the last desk in the classroom. He however, sees it clearly when sitting on
the front desk at an approximate distance of 2m from the blackboard. Draw ray
diagrams to illustrate the formation of image of the blackboard writing by his eye-lens
when he is seated at the (i) last desk (ii) front desk. Name the kind of lens
that would help him to see clearly even when he is seated at the last desk.
Draw a ray diagram to illustrate how this lens helps him to see clearly.
12.
A beam of white light falling on a glass prism
gets split up into seven colours marked 1 to 7 as shown in the diagram. A
student makes the following statements about the spectrum observed on the
screen.
[2] (a)
The colours at positions marked 3 and 5 are similar to the colour of the sky
and the core of a hard boiled
egg respectively. Is the above statement made by the student correct or
incorrect? Justify.
(b) Which two positions
correspond closely to the colour of
[1] (i) a solution of
potassium permanganate?
[1] (ii) ‘danger’ or
stop signal lights?
[2]Draw a line segment
of length 7 cm and divide it in the ratio 2 : 3. Measure the two parts.
13.
[2]Construct
a triangle with sides 5 cm, 6 cm and 7 cm and then construct another triangle
similar to it whose sides are 2/3of the corresponding sides of the first
triangle.
14.
[2]Construct
a triangle similar to a given triangle with sides 6 cm, 7 cm, and 8 cm and
whose sides are 1.4 times the corresponding sides of the given triangle.
15.
[2]Draw a
triangle with side BC = 6 cm, B = 45° and A = 75°.
16.
[2]Let
ABC be a right triangle in which AB = 6 cm, BC = 8 cm andB = 90°. BD is the perpendicular from B on AC. The circle
through B, C and D is drawn. Construct the tangents from A to this circle.
17.
[2]Draw a
circle. Take a point outside the circle. Construct the pair of tangents from
this point to the circle (without using its centre).
18. [2]Draw a
circle of diameter 12 cm. From a point 10 cm away from its centre, construct a
pair of tangents to the circle. Measure the lengths of the tangent segments,
19.
[3]Construct
a DABC with BC = 5cm, ÐA = 70° and median through A is 3.5 cm. Write the
steps of construction.
