This muscular force acts against the force of gravity that pulls the bucket towards the ground. However, he can see the objects placed at points P and Q, but cannot see the object placed at point R as shown in the given figure. In irregular reflection, are the reflected rays parallel or not? We are able to see the moon because it reflects the sunlight falling on it. Take a paper sheet and make a small hole in its centre. Which kind of spherical mirrors are used in vehicles? Close this end of the tube by a ground glass plate. Can you see objects outside the room? What is meant by lateral inversion? Question 7 Identify the part which vibrates to produce sound in the following instruments. This circular tube is now closed at one end with a cardboard disc.
It has a large number of steep and high mountains. The Braille system, for visually challenged persons,, is a a visual aid b auditory aid c tactual aid The eye lens is d electronic aid Answer: c Question 15. When the reflected rays are not parallel, the reflection is known as diffused or irregular reflection. Eye problems happen due to lack of a Vitamin C b Vitamin D c Vitamin A d Vitamin B complex Answer: c Question 17. Answer: In irregular reflection the reflected rays are not parallel. They have on their retina a large number of rod cells and only a few cones. When one body rolls over the surface of another body, the resistance to its motion is called the rolling friction.
The cones are sensitive to bright light and can sense colours. The eye lens is a concave b convex c planoconcave d planoconvex Answer: b Question 16. The topic force and pressure are one of the important concepts in science. The smallest cell is 0. You will be able to study better and keep improving in the tests. At one end of the rod, two leaves of aluminium foil are fixed and at the other end, there is a metal disc.
Since like charges repel each other, two charged balloons repel each other. You will come across questions where the applied force changes the shape of an object. Due to this, light reaches to us faster than sound. This prism is fixed into a circular cardboard tube. With our help, you can prepare for your examinations better and understand the complex concepts clearly. Images are not formed by irregular reflection.
Therefore, despersion of light into a spectrum takes place. Answer: Cones are the nerve endings which are sensitive to colour light. Sound can travel through a gases only b solids only c liquids only d solids, liquids and gases. Same charges repel each other and opposite charges attract each other. This end is now closed by a round glass plate allowing enough space for the coloured glass pieces to move.
It is the unlike charges that attract each other. As a result, his state of motion gets changed. Here you will be facing questions which will give you clarity regarding various aspects of this chapter and will help you to solve questions from this chapter easily. We want our students to understand the basic and advanced concepts of class 8 science - that is why our lectures are live and not pre-recorded. When all the parallel rays reflected from a plane surface are not parallel, the reflection is called diffused or irregular. Kaleidoscope is made up of three rectangular mirror strips each about 15 cm long and 4 cm wide. Fix them with a few thick chart papers in a slightly long circular tube.
With time, students develop an interest in the subjects they learn and this is what we at Vedantu wish to achieve. A synthetic fibre is a chain of small units chemical substances joined together. Answer: Some of the precautions are as follows: i Try to find an open field away from tall buildings, installations, tall trees, and electric wires and poles. Answer: b The rod becomes positively charged, while the cloth has a negative charge. When the metal disc is touched with a charged body, the aluminium strips move away from each other. Answer: To be seen an object, the sense of vision and light are required. The objects outside the room can only be seen if there is light outide.
The substances which reduce friction force are called. Answer: Iris controls the amount of light entering into the eyes. Hence, there is no change in the state of motion. Due to this reason, it will give a diffused reflection. At what angle are they inclined with respect to each other? Question 10 Explain in what way noise pollution is harmful to humans. This is because water makes the marble surface smooth.