Reflected waves are simply those waves that are neither transmitted nor absorbed, but are reflected from the surface of the medium they encounter. The amount of incident-wave energy that is reflected from a surface depends on the nature of the surface and the angle at which the wave strikes the surface. The amount of wave energy reflected increases as the angle of incidence increases. The reflection of energy is the greatest when the wave is nearly parallel to the reflecting surface.

Correct Option: B

Reflected waves are simply those waves that are neither transmitted nor absorbed, but are reflected from the surface of the medium they encounter. The amount of incident-wave energy that is reflected from a surface depends on the nature of the surface and the angle at which the wave strikes the surface. The amount of wave energy reflected increases as the angle of incidence increases. The reflection of energy is the greatest when the wave is nearly parallel to the reflecting surface.

As per the norm, the permissible noise level in residential areas is 45 db during night time, 55 db during day and in commercial areas it is 55 db during night and 65 db during day.

Correct Option: A

As per the norm, the permissible noise level in residential areas is 45 db during night time, 55 db during day and in commercial areas it is 55 db during night and 65 db during day.

Laser light is very different from normal light. It is very directional, has a very tight beam and is very strong and concentrated. The light released is monochromatic. It contains one specific wavelength of light (one specific colour).

Correct Option: D

Laser light is very different from normal light. It is very directional, has a very tight beam and is very strong and concentrated. The light released is monochromatic. It contains one specific wavelength of light (one specific colour).

The SI unit of quantity of electric charge is the coulomb, which is equivalent to about 6.242×1018 e (e is the charge of a proton). Hence, the charge of an electron is approximately -1.602×10-19 C. The coulomb is defined as the quantity of charge that has passed through the cross section of an electrical conductor carrying one ampere within one second.

Correct Option: B

The SI unit of quantity of electric charge is the coulomb, which is equivalent to about 6.242×1018 e (e is the charge of a proton). Hence, the charge of an electron is approximately -1.602×10-19 C. The coulomb is defined as the quantity of charge that has passed through the cross section of an electrical conductor carrying one ampere within one second.

An electric charge always produces an electric field, regardless of speed, and a moving charge generates a magnetic field. An electric current passing through a conductor produces a magnetic field because it has many charges in motion.

Correct Option: A

An electric charge always produces an electric field, regardless of speed, and a moving charge generates a magnetic field. An electric current passing through a conductor produces a magnetic field because it has many charges in motion.