Meaning of Gravitation Force Meaning of Friction Force Meaning of Centripetal Force What sort of fuse would be required by the following devices? (Assume 230 volts for voltage, and keep in mind that fuses are found in 3, 5 and 13 A varieties.) A cooker with a power of 2000 watts A hair dryer with a power of 500 watts A television with a power of 1000 watts 5. List the electromagnetic spectrum, and explain the different uses of each. 6. Meaning of dispersion

(Generally, unrelated multipart questions are asked as separate questions. I will address some of the parts).
1) Gravitation force is the force of attraction that exists between any two bodies. The force is directly proportional to the product of their masses and inversely proportional to the square of the distance between them. This force keeps us on the ground and also is demonstrated when we see an apple fall from the tree.
2) Friction force is the force that resists the motion between two bodies in contact. If you push a book on a flat table, it will come to a rest after some time. It is the friction force that stops it. Depending on whether the bodies are in relative motion or not, this force can be static friction or dynamic friction.
3) Centripetal force— When a body is moving along a curved path, a force acts on the body directed toward the center of curvature of the path. This force is known as the centripetal force. When a car is turning around a roundabout, this force acts on it. Similarly, when the Moon orbits the Earth, the force of gravity provides the centripetal force.
4) Remember, power = voltage x current or P = V x I
So, if P = 2000 watts and V = 230 V
then I = P/V = 2000/230 = 8.69 A. This means a fuse of 13 A is needed.
5) The electromagnetic spectrum consists of radio waves, microwaves, infrared, visible, ultraviolet, X-rays and gamma rays.
6) Dispersion: In optics, dispersion refers to the splitting of visible light into different colors. It can be demonstrated by using a prism.
Hope this helps.