Ultraviolet radiation is used to kill microorganisms, molds and fungus in various environmental applications. UV sterilization is used for air-purification systems, water purification, aquarium and pond maintenance, laboratory hygiene and food and beverage protection.

Correct Option: D

Ultraviolet radiation is used to kill microorganisms, molds and fungus in various environmental applications. UV sterilization is used for air-purification systems, water purification, aquarium and pond maintenance, laboratory hygiene and food and beverage protection.

A microphone converts sound energy to electrical energy this energy level is used as an output using same energy level amplified or it could be used to record those same energy output and pattern too be played again. Sound waves strike a plastic or thin metal diaphragm, causing in to move an attached coil within a strong magnetic field. The induced current duplicates the frequency of the sound wave.

Correct Option: C

A microphone converts sound energy to electrical energy this energy level is used as an output using same energy level amplified or it could be used to record those same energy output and pattern too be played again. Sound waves strike a plastic or thin metal diaphragm, causing in to move an attached coil within a strong magnetic field. The induced current duplicates the frequency of the sound wave.

A solid conductive metal contains mobile, or free electrons, originating in the conduction electrons. When a metal wire is connected across the two terminals of a DC voltage source such as a battery, the source places an electric field across the conductor. The moment contact is made, the free electrons of the conductor are forced to drift toward the positive terminal under the influence of this field. The free electrons are therefore the charge carrier in a typical solid conductor.

Correct Option: A

A solid conductive metal contains mobile, or free electrons, originating in the conduction electrons. When a metal wire is connected across the two terminals of a DC voltage source such as a battery, the source places an electric field across the conductor. The moment contact is made, the free electrons of the conductor are forced to drift toward the positive terminal under the influence of this field. The free electrons are therefore the charge carrier in a typical solid conductor.

Assuming air to be an ideal gas, the speed of sound c depends on temperature only, not on the pressure or density. As air temperature increases, so does the speed of sound and vice versa. This is due to the individual air particles having extra kinetic energy at higher temperatures and lesser at lower temperatures.

Correct Option: D

Assuming air to be an ideal gas, the speed of sound c depends on temperature only, not on the pressure or density. As air temperature increases, so does the speed of sound and vice versa. This is due to the individual air particles having extra kinetic energy at higher temperatures and lesser at lower temperatures.

When a metal plate with a circular hole at its centre is heated, definitely along with the areal expansion of the plate the diameter of the circular hole also increases. Using the differential equations of coefficients of expansions, we find that the hole radius increases at the same linear rate as the metal.

Correct Option: A

When a metal plate with a circular hole at its centre is heated, definitely along with the areal expansion of the plate the diameter of the circular hole also increases. Using the differential equations of coefficients of expansions, we find that the hole radius increases at the same linear rate as the metal.