What should be the resistance of a heating coil which will...

What should be the resistance of a heating coil which will be used to raise the temperature of $500 \mathrm{~g}$ of water from $28^{\circ} \mathrm{C}$ to the boiling point in $2.0$ minutes, assuming that 25 percent of the heat is lost? The heater operates on a $110-V$ line.

Key Concepts

Specific Heat Capacity

This concept describes the amount of energy required to increase the temperature of a unit mass of a substance by one degree Celsius. It is a fundamental parameter in thermodynamics that allows calculation of the thermal energy needed to achieve a desired temperature change in a material.

Energy Efficiency

Efficiency in energy transfer refers to the fraction of the supplied energy that is usefully converted into the desired form, such as thermal energy. In practical applications, some energy is always lost, so accounting for efficiency is crucial when determining the total energy input required to achieve a specific outcome.

Electrical Power and Resistive Heating

This concept involves understanding how electrical energy is converted into heat in a resistor. The power dissipated by a resistor is given by the relation P = V² / R, where V is the voltage and R is the resistance. This relation is essential when designing heating devices, as it links electrical parameters with thermal output.

Energy Conversion and Conservation

The principle of energy conversion and conservation states that the total energy in a closed system remains constant, though it may change forms. In the context of heating, the electrical energy supplied is converted into thermal energy, and careful accounting of all energy transformations, including losses, is necessary for accurate system design.

Transcript

Please give Ace some feedback