Class VII Physics

Time: 2 hrs Total Marks: 75

General Instructions: 1. All questions are compulsory. 2. Questions 1 to 15 carry one
mark each. 3. Questions in 2A and 2B carry one mark each. 4. Questions in 3A and
3B carry one mark each. 5. Question in 4A and 4B carries one mark each. 6.
Questions in 5A carry one mark each and 5B carry five marks. 7. Questions in 6
carry two marks each. 8. Question 7A and 7B carry ten marks in total.

Question 1
Choose the correct answer out of the four available choices given under
each question. [15]

1. A body is said to be in uniform motion when it travels an

(a) Unequal distance in an equal interval of time (b) unequal distance in
an unequal interval of time (c) equal distance in an unequal interval of
time (d) equal distance in an equal interval of time.
2. The ratio of C.G.S. to M.K.S. unit of acceleration is:
(a) 1 : 1 (b) 1 : 10 (c) 1 : 100 (d) 10 : 1
3. The nature of the image formed by a convex mirror is always
(a) Real and inverted (b) Real and erect (c) Virtual and erect (d) Virtual and
inverted .
4. The unit of speed is
(a)Meter/𝑠𝑒𝑐𝑜𝑛𝑑2 (b) second/metre (c) meter second (d) meter/second
5. Why does ice float on water?
(a) Because density of ice is higher than that of water. (b) Because density
of ice is less than that of water. (c) Because density of ice and water is
the same but ice is a solid. (d) Ice does not float on water.
6. When is a body said to be in motion?
(a) When it moves in a straight line (b) When it moves in a circular path (c)
When it move in a swinging motion (d) All of the above.
7. What is the weight of a body of mass of 25 kg? (g = 9.8 m/𝑺𝟐 )
(a) 25N (b) 25 kg (c) 245 N (d) 245 kg .
8. How much distance does a car cover when it moves 20 km to the east
and then 60 km to the west?
(a) 60 km (b) 80 km (c) 20 km (d) 40 km .
9. If the radius of curvature of a spherical mirror is 34.52 cm, then the
focal length of that spherical mirror is
(a) 17.26 cm (b) -34.52 cm (c) 69.04 cm (d) 34.52 cm .
10. A car increases its speed from 20 km/h to 40 km/h in 10 seconds. Its
acceleration is:
(a) (5/9) m/s² (b) 2 m/s² (c) (-5/9) m/s² (d) -2 m/s²
11. In a concave mirror, the image is inverted and the same size as the
object when the object is placed at the
(a) Principal Focus (b) Centre of curvature (c) Between the focus and the
centre of curvature (d) Between the focus and the pole of mirror .
12. If we want to determine the volume of a solid by immersing it in
water, the solid should be
(a) lighter than water (b) heavier than water (c) insoluble in water (d) heavier
than water and insoluble in it .
13. In hot countries, it is preferred to wear light colours on a hot day
because
(a) light colours are poor absorbers of heat (b) light colours are good
radiators of heat (c) light colours are good absorbers of heat (d) light
colours are poor radiators of heat.
14. Radius of curvature of a concave mirror is always _________ to the
mirror.
(a) parallel (b) perpendicular (c) inclined at 60 0 (d) inclined at 450 .
15. Which of the following is used to make a periscope?
(a) Concave mirror (b) Convex mirror (c) Plane mirror (d) Lens .
Question 2 (A)
Answer the following questions in one word or one sentence. [5]
1.What is meant by rectilinear motion?
2. State the relationship between focal length and radius of curvature of a
spherical mirror.
3. Give the relation between acceleration, change in velocity and time.
4. Name two types of spherical mirrors.
5. State the relationship between focal length and radius of curvature of a
spherical mirror.
(B) Fill up the blanks and rewrite the sentences: [5]
1. The weight of an object on the moon is about __________ of that on the
Earth.
2. A stone tied to a string has ___________ motion when it is whirled
around.
3. The straight line passing through the centre of curvature and pole of a
spherical mirror is called its ___________.
4. The image formed by a _________ mirror is always virtual and small in size.
5. When a body travels with uniform velocity, its acceleration is_________.
Question 3
(A)Match the item in column I with the appropriate item in column II. [5]
Column A Column B
Kg/m3 Plane mirror
Velocity A concave mirror
The image is erect and the same size as Wood
the object
Used by dentist to see enlarged image of Density
teeth
Opaque medium Vector
(B) Define the following: [5]
1. Rest
2. Virtual Image.
3. Thermal energy.
4. Rotational motion.
5. Angle of incidence.
Question 4
(A) Identify and classify the following types of motions as circular,
periodic, vibratory or random motion: [5]
The motion of the Earth around the
Sun
The motion of a plucked string of a
guitar
Motion of a flying bird
Motion of tides in the sea
The swinging pendulum of a wall
clock

(B) Give one word for the following. [5]

1. Shadow region of total darkness in front of an opaque objects where no
light enters.
2. The motion in which an object does not cover equal distances in equal
intervals of time.
3. At infinity it gives a real, inverted and diminished image.
4. These are based on the nuclear fusion of Uranium-235.
5. When an object is placed over a liquid whose density is less than the
density of the object, the object will.
Question 5
(A) State whether the following statements are True or False. [5]
1. Inertia is the specific property of a body by virtue of which the body
changes its state of rest by itself.
2. Formation of images s done by ray diagram.
3. A piece of iron (density 7.6 g/cm3), floats in mercury (density 13.6 g/cm3).
4. For a moving object, displacement can be zero, but distance can never be
zero.
5. A spring balance is used to measure the weight of a body.
(B)
1. Draw ray diagrams to show the image formation by a concave mirror,
when it is placed (i) beyond C (ii) at C. [3]
2. What are transparent objects, translucent objects and opaque objects?
Give examples. [2]
Question 6
Answer the following questions in short:
1. State the laws of reflection. [2]
2. If an object is placed at a distance of 10 cm in front of a plane mirror,
how far would the object be from its image? [2]
3. The distance between two stations is 560 km. A train takes 480
minutes to cover this distance. Calculate the speed of the train. [2]
4. A stone of mass 25 g is immersed completely in water contained in a
measuring cylinder. The initial level of water was 50 cm³ and after
lowering the stone it was found to be 60 cm³. Find the density of the
stone? [2]
5. A cyclist travels a distance of 4 km from P to Q and then a distance of
3 km at right angle to PQ. What is the displacement of the cyclist? [2]
Question 7
(A)
1. A body moving with a velocity 5m/s achieves a velocity of 20 m/s in 30
s. Calculate the acceleration of the body? [3]
2. What is meant by kinetic energy and potential energy? What is the
relationship between calorie and joule? [4]
(B)
1. Give three differences between concave and convex mirrors. [3]