Physics Quiz 6

Hypermetropia, also known as long-sightedness, is a defect of vision in which a person can't see the nearby object clearly (appears blurred), though can see the distant objects clearly. The near point of a hypermetropic eye is greater than 25 cm.

When a body is thrown upward, the height attained by that body is independent of the mass and depends on the initial speed of the body and the value of g. So, two stones of unequal masses are thrown vertically up with the same velocity they will reach the same height.

A fuse wire is characterized by high resistance and low melting point. As a high amount of current is passing, resistances of the fuse wire have to be large due to which the heat produced will be high and it is broken down immediately.

Complementary colours are pairs of colours which, when combined or mixed, cancel each other out by producing white or black. Examples of complementary colour combinations are: Red and green; yellow and blue (purple).

Ice is packed in sawdust because it is a poor conductor of heat. The air filled in the fine pores of sawdust is an insulator of heat. This air does not allow heat from outside to pass to the ice thereby preventing its melting.

Aperture refers to the opening of a lens's diaphragm through which light passes. It controls the brightness of the image that passes through the lens and falls on the image sensor. The camera sensor size is one of the key elements that affect the sharpness of an image.

The apparent weight of a man in a lift is less than the real weight when the lift is going down with an acceleration. When a lift accelerates upwards, the apparent weight of the person inside it increases; and when a lift accelerates downwards, the apparent weight of the person inside it decreases.

A geostationary satellite is an earth-orbiting satellite, placed at an altitude of approximately 35,800 km directly over the equator, that revolves in the same direction the earth rotates (west to east). At this altitude, one orbit takes 24 hours, the same length of time as the earth requires to rotate once on its axis. So they seem stationary, relative to the Earth's surface.

Heat transfer horizontally within the atmosphere is called advection. Advection is the transfer of heat or matter by the flow of a fluid, especially horizontally in the atmosphere or the sea. The horizontal movement of the air is comparatively more significant than the vertical movement.

Surface tension is the tendency of liquid surfaces at rest to shrink into the minimum surface area possible. The hair of a shaving brush clings together when removed from water due to Surface tension.