Question

Physics (30 marks)

I. Name the following: 1x3=3

a) The phenomenon in which a ray of light travels from one medium to another, bends at

the boundary between the two mediums.

b) An imaginary line passing through the pole and the centre of curvature of the spherical

mirror.

c) An optical phenomenon which causes an illusion of puddles of water on a hot road.


II. Write True or False: 1x×3=3

a) The more the speed , the more is the Kinetic energy of the object in motion.

b) A 25W bulb converts 25J of energy in one hour.

c) Kinetic energy is also called stored energy.


III. Choose the correct option to fill in the blanks:1×3=3

a) A large force can create a small pressure of it is spread out over a ______(wide/small)

area.

b) Pressure in a liquid ______ (increase/decrease) with depth.

c) Heavy vehicles such as trucks and buses that carry loads have _____ (thick and

wide/thin and small) tyres to exert less pressure on the ground.


IV. Write the position and nature of the image formed in a concave mirror if the object is kept

a) At F

b) Beyond C.

Also draw the ray diagram. (3+3)


V. Short answer questions (Any 5) : 2×5=10

1. What do you mean by refraction?

2. What do you mean by dispersion of light?

3. Write any two rules for making ray diagrams for spherical mirror?

4. How do you measure work done?

5. Define power. What is its SI unit?

6. What are the two factors that affect the moment of force and how?

7. Define law of conservation of energy.


VI. Long answer questions (Any 1) : 5x1=5

1. List the uses of concave and convex mirrors.

2. List the differences between energy and power.

3. a) Define torque. Explain with two examples from daily life.

b) Explain liquid pressure. On what factors does it depend​

Answer 1

Answer:

1.AReflection of light

B. Principal axis

C. dont no