Concave mirrors are used in makeup or shaving mirrors. When shaving or applying makeup, a person holds the mirror close to her face. This allows him to see an enlarged image of him face, which is helpful for applying makeup or shaving correctly.

Correct Option: B

Concave mirrors are used in makeup or shaving mirrors. When shaving or applying makeup, a person holds the mirror close to her face. This allows him to see an enlarged image of him face, which is helpful for applying makeup or shaving correctly.

The acceleration due to gravity of earth is the rate of increase of velocity of a body falling freely towards the earth. At a given place, the value of acceleration due to gravity is constant but it varies from one place to another place on the earth surface. It is due to this fact that earth is not a perfect sphere. It is flattened at the poles and bulges out at the equator. The value of ‘g’ is minimum at the equator and maximum at the poles.

Correct Option: C

The acceleration due to gravity of earth is the rate of increase of velocity of a body falling freely towards the earth. At a given place, the value of acceleration due to gravity is constant but it varies from one place to another place on the earth surface. It is due to this fact that earth is not a perfect sphere. It is flattened at the poles and bulges out at the equator. The value of ‘g’ is minimum at the equator and maximum at the poles.

The decibel (dB) is a logarithmic unit that indicates the ratio of a physical quantity (usually power or intensity) relative to a specified or implied reference level. A ratio in decibels is ten times the logarithm to base 10 of the ratio of two power quantities.

Correct Option: C

The decibel (dB) is a logarithmic unit that indicates the ratio of a physical quantity (usually power or intensity) relative to a specified or implied reference level. A ratio in decibels is ten times the logarithm to base 10 of the ratio of two power quantities.

A geostationary orbit is a circular orbit 35,786 kilometres above the Earth’s equator and following the direction of the Earth’s rotation. Communications satellites and weather satellites are often given geostationary orbits, so that the satellite antennas that communicate with them do not have to move to track them, but can be pointed permanently at the position in the sky where they stay.

Correct Option: A

A geostationary orbit is a circular orbit 35,786 kilometres above the Earth’s equator and following the direction of the Earth’s rotation. Communications satellites and weather satellites are often given geostationary orbits, so that the satellite antennas that communicate with them do not have to move to track them, but can be pointed permanently at the position in the sky where they stay.

Car head lights have concave mirrors because it collects and focuses as much as possible of the light from the bulb and send it out as a fairly tight beam in one direction only. The bulb of the head light is placed at the focal point. The reflected light is parallel and gives more visibility to the driver at night.

Correct Option: B

Car head lights have concave mirrors because it collects and focuses as much as possible of the light from the bulb and send it out as a fairly tight beam in one direction only. The bulb of the head light is placed at the focal point. The reflected light is parallel and gives more visibility to the driver at night.