In How to know, about science and technology series we will provide you information about science and technology, We are in making part of series and every part will contain 8-10 scientific questions and answer !
WHY DO THINGS LOOK NEARER UNDERWATER?
If you try to pick up an object in a A tank or pool of water, you’ll find that it is deeper than it looks, The reason for this is that light rays from the object bend as they leave the water.
Rays of light from an object travel up through the water to the surface, As they move from the water into the air, the rays bend towards the surface of the water.
However, our eyes always assume that light travels from anything we see in a straight line without bending, We see the object in the position it would have if light travelled in a straight line to the eyes, It therefore appears to be higher in the water.
HOW DOES A MAGNIFYING GLASS WORK?
Light rays from an object pass through the magnifying glass to reach your eyes. The glass bends the rays, which reach your eyes as if they were coming from a bigger object.
The magnifying glass is a lens. Refraction causes light rays passing through a lens to bend at the surfaces between the air and the glass. The glass is a convex lens, which bends light rays from all points on the object towards each other. This causes an enlarged image of the object to appear behind the glass.
HOW DOES A MIRROR WORK?
When you look in a mirror, light rays go from you and strike the mirror. The rays bounce off the mirror and come back to your eyes. You see an exact image of yourself, but it is reversed.
A mirror is made of glass with a shiny coating on the back. The light rays pass through the glass and are reflected from the coating.
Light rays are reflected back by a flat mirror at the same angle as they strike the mirror. This makes an image seen in a flat mirror appear to be the same size and shape as the object.
HOW DOES A PERISCOPE WORK?
You can use a periscope to see A something from a higher level as if you were taller. A simple periscope has two sloping mirrors, one above the other. Light from an object strikes the top mirror, which reflects it to the bottom mirror. This mirror reflects the light into your eyes, and you see an image of the object.
A submarine has a periscope so that it can observe ships on the surface when it is submerged. This periscope works in the same way as a simple periscope, but has prisms instead of mirrors to give a high- quality image.
HOW MUCH CAN MICROSCOPE MAGNIFY?
You can see objects highly magnified in an optical microscope. The most powerful microscope can make an object look as much as 2500 times bigger than it really is. Electron microscopes can make things look even bigger still.
The focusing knob is turned to bring the objective lens very close to the object. This lens makes light rays from the object meet, They form a magnified image of the object inside the tube of the microscope. The light
rays go on to the eyepiece lens, which magnifies the image more.
HOW DOES AN ELECTRON MICROSCOPE WORK?
The electron microscope can magnify objects by as much as a million times. Instead of using light rays, it works with beams of tiny particles called electrons.
The image is seen on a screen or may be photographed. The electron microscope works like an optical microscope with a condenser and objective and eyepiece (projector) lenses. They produce an electron image using a beam of electrons passed through the object. The projector forms this image on a fluorescent screen.
WHAT DO HYDRAULIC MACHINES DO?
Hydraulic machines operate brakes on vehicles, presses and hammers for shaping metal objects, and lifting and digging machines. The hydraulic systems in these machines work with fluid at high pressure.
Hydraulic systems are used in machines that have to create a very powerful force over a short distance. For example, a hydraulic jack raises a large vehicle just off the ground.
A hydraulic system contains two pistons that move up and down in cylinders,
HOW DOES A GYROCOMPASS WORK?
A gyrocompass shows the direction A of north like a magnetic compass, But instead of using magnetism, it contains a spinning disc like a gyroscope, The axle of the disc always points north A card marked with directions shows which way north lies.
The disc or rotor of the gyrocompass is powered by an electric motor so that it spins non-stop. The axle of the rotor always points in the same direction and it can be set to point north.
Also Read –
- Science And Technology Question & Answer – Part 1
- Science And Technology Question & Answer – Part 2
- Science And Technology Question & Answer – Part 3
- Science And Technology Question & Answer – Part 4
- Science And Technology Question & Answer – Part 5
- Science And Technology Question & Answer – Part 6
- Science And Technology Question & Answer – Part 7
- Science And Technology Question & Answer – Part 8
- Science And Technology Question & Answer – Part 9
- Science And Technology Question & Answer – Part 11
- Science And Technology Question & Answer – Part 12