Ohmic conductors are conductors that obey Ohm’s law, that is Voltage/Current ratio is constant; in other words, the equation Resistance = Voltage/Current is obeyed. An Ohmic conductor’s resistance does not change with varying current. Metallic conductors such as silver are Ohmic conductors.

Correct Option: D

Ohmic conductors are conductors that obey Ohm’s law, that is Voltage/Current ratio is constant; in other words, the equation Resistance = Voltage/Current is obeyed. An Ohmic conductor’s resistance does not change with varying current. Metallic conductors such as silver are Ohmic conductors.

Solar, wind and hydro power are examples of cleanest energy sources. According to a new US study, Greenhouse gases produced over the lifetime of a wind turbine are less than that of fossil-fuel based energy sources and most other renewables. Only ocean energy (wave and tidal) and hydropower have lower emissions than wind. As a clean, fuel-free source of energy, wind turbines create energy without generating the damaging pollutants.

Correct Option: D

Solar, wind and hydro power are examples of cleanest energy sources. According to a new US study, Greenhouse gases produced over the lifetime of a wind turbine are less than that of fossil-fuel based energy sources and most other renewables. Only ocean energy (wave and tidal) and hydropower have lower emissions than wind. As a clean, fuel-free source of energy, wind turbines create energy without generating the damaging pollutants.

Silver has the best thermal conductivity of 429 W/mK at RT (295K). It is followed by copper, gold and aluminium. Metals generally have very good electrical conductivity, that leads to high thermal conductivity. There is a rule governing the relation between electrical conductivity and thermal conductivity, called Wiedemann-Franz Law.

Correct Option: C

Silver has the best thermal conductivity of 429 W/mK at RT (295K). It is followed by copper, gold and aluminium. Metals generally have very good electrical conductivity, that leads to high thermal conductivity. There is a rule governing the relation between electrical conductivity and thermal conductivity, called Wiedemann-Franz Law.

Reflection of sound waves off of surfaces lead to one of two phenomena - an echo or a reverberation.The echo is produced due to hitting of the sound waves with the obstacles which makes the sound to reflect back.Echoes occur when a reflected sound wave reaches the ear more than 0.1 seconds after the original sound wave was heard.

Correct Option: A

Reflection of sound waves off of surfaces lead to one of two phenomena - an echo or a reverberation.The echo is produced due to hitting of the sound waves with the obstacles which makes the sound to reflect back.Echoes occur when a reflected sound wave reaches the ear more than 0.1 seconds after the original sound wave was heard.

Any object moving in a circle (or along a circular path) experiences a centripetal force. It is this physical force that pushes or pulls the object towards the center of the circle. In the case of a car moving along a curve, as it makes a turn, the force of friction acting upon the turned wheels of the car provides centripetal force required for circular motion. The net force on a car travelling around a curve is the centripetal force, Fc = m v2 / r, directed toward the center of the curve.

Correct Option: C

Any object moving in a circle (or along a circular path) experiences a centripetal force. It is this physical force that pushes or pulls the object towards the center of the circle. In the case of a car moving along a curve, as it makes a turn, the force of friction acting upon the turned wheels of the car provides centripetal force required for circular motion. The net force on a car travelling around a curve is the centripetal force, Fc = m v2 / r, directed toward the center of the curve.