Suppose you are in a dark room. Can you see objects in the room? Can you see objects outside the room. Explain.
Solution and Explanation
We can see any object, when light reflected by that object reaches to our eyes. But in the dark room, no light is reflected by the object. Hence, we are not able to see the objects in dark room. But if there is light outside the room, we can see the objects lying out there.
Top CBSE Class VIII Science Questions
Select the correct word from the following list and fill in the blanks.
float, water, crop, nutrients, preparation- The same kind of plants grown and cultivated on a large scale at a place is called ____.
- The first step before growing crops is ____ of the soil.
- Damaged seeds would ____ on top of water.
- For growing a crop, sufficient sunlight and ____ and ____ from the soil are essential.
- List conditions under which combustion can take place.
- Match items in column A with those in column B.
A B (i) Kharif crops (a) Food for cattle (ii) Rabi crops (b) Urea and super phosphate (iii) Chemical fertilizers (c) Animal excreta, cow dung urine and plant waste (iv) Organic manure (d) Wheat, gram, pea (e) Paddy and maize - Fill in the blanks:
- Burning of wood and coal causes ___ of air.
- A liquid fuel, used in homes is ___.
- Fuel must be heated to its ___ ___ before it starts burning.
- Fire produced by oil cannot be controlled by ___.
- Explain how the use of CNG in automobiles has reduced pollution in our cities.
Top CBSE Class VIII Reflected Light Can be Reflected Again Questions
- Describe an activity to show that the incident ray, the reflected ray and the normal at the point of incidence lie in the same plane.
- Mention against each of the following whether regular or diffused reflection will take place when a beam of light strikes. Justify your answer in each case.
1. Polished wooden table
2. Chalk powder
3. Cardboard surface
4. Marble floor with water spread over it
5. Mirror
6. Piece of paper - Describe the construction of a kaleidoscope.
- Choose the correct option.
Angle of incidence is equal to the angle of reflection. - What is the angle of incidence of a ray if the reflected ray is at an angle of 90° to the incident ray?
Top CBSE Class VIII Questions
- Solve the following equation and check your result: \(3x = 2x + 18\)
- Solve and check result: \(5t - 3 = 3t - 5\)
- Solve and check result: \(5x + 9 = 5 + 3x\)
- Solve and check result: \(4z + 3 = 6 + 2z\)
- Solve and check result: \(2x - 1 = 14 - x\)
Concepts Used:
Reflection of Light
When a light ray falls on any object, it is bounced back from the object. This process is known as the Reflection of light. The light reflected from the object falls into our eyes, making the object visible to us. All the things we see around us are because of reflection.
The reflection of light depends on the type of object. A polished or smooth surface reflects most of the light falling on it, while a rough surface absorbs some amount of light and reflects back the rest of the light. The direction of reflected rays depends upon the surface of the object.