BOOK 8 Unit 12:LIGHT

BOOK 8 Unit 12:LIGHT

Revision

Let's Test your understanding

Lesson 1 : Light is travelling in straight line

Multiple Choice

The visible light is composed of several spectral of colors with different frequencies and wavelength. What is the correct order of arrangement of these colors?

• a. VIGBYOR

• b. ROYGVIB

• C. ROYGBIV

• d.ROYBGIV

Multiple Choice

A straight glass rod appears to bend when placed in a beaker of water. What is the best explanation for this phenomenon?

• a.The water is warmer than the air

• b.Light travels faster in water than in air

• c.Light is reflected at the air-water interface

• d.Light is refracted as it crosses at the air- water interface

Multiple Choice

Which color in the visible light has the lowest frequency and the least energy?

• a. Red

• b. Violet

• c. Blue

• d. Orange

Multiple Choice

Which color in the visible light has the highest frequency and the most energy?

• a.Violet

• b. Red

• c. Blue

• D. indigo

Fill in the Blanks

c- When light rays fall on a rough surface, they are

in all directions.

Multiple Choice

The ray of light that strikes a mirror is called ________

• an incident ray

• a reflected ray

• a normal ray

Multiple Choice

The Law of reflection states that - The angle of incidence is .................. the angle of reflection

• equal to

• double

• half

Multiple Choice

4. If the angle of incidence is 45 degree, what is the angle of reflection?

• 90°

• 45°

• 180°

Multiple Choice

3. The angle between the reflected ray and the normal line is called the:

• Angle of incidence

• Angle of reflection

• angle of convergent

Multiple Choice

2. The imaginary line perpendicular to the mirror is called the

• Incident ray

• reflected ray

• normal line

Multiple Choice

A _________ forms when the path of light is blocked.

• sun

• circle

• line

• shadow

Multiple Choice

A copy of an object formed by reflected or refracted rays of light

• image

• regular reflection

• reflection

• diffuse reflection

Multiple Choice

Why can you see most objects?

• they emit light

• light refracts through them

• light reflects off them

• They absorb light

Multiple Choice

a. Objects that give off their own light is called __________

• non luminous

• Opaque

• luminous

Multiple Choice

a. Objects that do not give off their own light is called __________

• opaque

• non luminous

• luminous

Multiple Choice

c -Moon is an example of the ________________ objects.

• non luminous

• None of them

• luminous

Well Done