Radio is the transmission of signals through free space by electromagnetic radiation of a frequency significantly below that of visible light, in the radio frequency range, from about 30 kHz to 300 GHz. These waves are called radio waves. Experiments were undertaken by Thomas Edison and his employees of Menlo Park. Edison applied in 1885 to the U.S. Patent Office for a patent on an electrostatic coupling system between elevated terminals. The patent was granted as U.S. Patent 465,971 on December 29, 1891. The Marconi Company would later purchase rights to the Edison patent to protect them legally from lawsuits.

Correct Option: C

Radio is the transmission of signals through free space by electromagnetic radiation of a frequency significantly below that of visible light, in the radio frequency range, from about 30 kHz to 300 GHz. These waves are called radio waves. Experiments were undertaken by Thomas Edison and his employees of Menlo Park. Edison applied in 1885 to the U.S. Patent Office for a patent on an electrostatic coupling system between elevated terminals. The patent was granted as U.S. Patent 465,971 on December 29, 1891. The Marconi Company would later purchase rights to the Edison patent to protect them legally from lawsuits.

Electric power is the rate at which electric energy is transferred by an electric circuit. The SI unit of power is the watt, one joule per second. Watt is named after the Scottish engineer James Watt who invented the Newcomen Steam Engine.

Correct Option: B

Electric power is the rate at which electric energy is transferred by an electric circuit. The SI unit of power is the watt, one joule per second. Watt is named after the Scottish engineer James Watt who invented the Newcomen Steam Engine.

Galileo’s experiment showed that if two bodies of unequal masses are dropped from the same height, the time required by them to reach the ground are equal. If they are thrown vertically upwards with the same initial velocity, then the ratio of the time required to reach the ground is equal to unity. This means that both of them will reach the same height.

Correct Option: C

Galileo’s experiment showed that if two bodies of unequal masses are dropped from the same height, the time required by them to reach the ground are equal. If they are thrown vertically upwards with the same initial velocity, then the ratio of the time required to reach the ground is equal to unity. This means that both of them will reach the same height.

On average, seawater in the world’s oceans has a salinity of about 3.5% (35 g/L, or 599 mM). Seawater is denser than both fresh water and pure water (density 1.0 g/ml ) because the dissolved salts add mass without contributing significantly to the volume. The density of sea water is high due to impurities and salts compared to river water as a result; the upthurst produced by the sea water on the ship is more than that of river water. When a ship enters a sea from a river ,the ship is elevated or uplifted due to the density of sea water and during the buoyant motion of the ship, as it would gain both potential and kinetic energy when rising in the fluid.

Correct Option: A

On average, seawater in the world’s oceans has a salinity of about 3.5% (35 g/L, or 599 mM). Seawater is denser than both fresh water and pure water (density 1.0 g/ml ) because the dissolved salts add mass without contributing significantly to the volume. The density of sea water is high due to impurities and salts compared to river water as a result; the upthurst produced by the sea water on the ship is more than that of river water. When a ship enters a sea from a river ,the ship is elevated or uplifted due to the density of sea water and during the buoyant motion of the ship, as it would gain both potential and kinetic energy when rising in the fluid.

Diffuse sky radiation is solar radiation reaching the Earth’s surface after having been scattered from the direct solar beam by molecules in the atmosphere. Of the total light removed from the direct solar beam by scattering in the atmosphere (approximately 25% of the incident radiation when the sun is high in the sky, depending on the amount of dust and haze in the atmosphere), about two-thirds ultimately reaches the earth as diffuse sky radiation. The sunlit sky is blue because air scatters short-wavelength light more than longer wavelengths. Since blue light is at the short wavelength end of the visible spectrum, it is more strongly scattered in the atmosphere than long wavelength red light. The result is that the human eye perceives blue when looking toward parts of the sky other than the sun.

Correct Option: C

Diffuse sky radiation is solar radiation reaching the Earth’s surface after having been scattered from the direct solar beam by molecules in the atmosphere. Of the total light removed from the direct solar beam by scattering in the atmosphere (approximately 25% of the incident radiation when the sun is high in the sky, depending on the amount of dust and haze in the atmosphere), about two-thirds ultimately reaches the earth as diffuse sky radiation. The sunlit sky is blue because air scatters short-wavelength light more than longer wavelengths. Since blue light is at the short wavelength end of the visible spectrum, it is more strongly scattered in the atmosphere than long wavelength red light. The result is that the human eye perceives blue when looking toward parts of the sky other than the sun.