Question

A \[3kW\] heater is connected with the supply of \[250volts\]A.C. to find its current and resistance.

Answer 1

Hint: An electric current could be a rate of flowing electric charge past a point or region. The property of a conductor by virtue of which it opposes the flow of electric current through it’s called resistance. Use ohm’s law to find the resistance.

Complete step-by-step solution:
A law that explains the flow of currents was derived by G.S. Ohm in 1828 before the physical mechanism accountable for the flow of currents was discovered. Let us imagine a conductor through which a current \[I\] is flowing and let \[V\] be the potential difference between the ends of the conductor. Then Ohm’s law states that
\[V = RI\]
Here, the constant of proportionality \[R\] is named as the resistance of the conductor. SI unit of resistance is the\[ohm\], denoted by the symbol\[\Omega \]. Resistance \[R\] depends on both the material and therefore the dimensions of the conductor.
Given that, Power \[P = 3kW = 3000W\]and voltage \[V = 250V\]
We know that, \[P = VI\]
\[I = \dfrac{P}{V} = \dfrac{{3000}}{{250}} = 12A\]
According to Ohm's law, Resistance is provided by the ratio of the voltage applied to the electric current which flows through it.
\[R = \dfrac{V}{I} = \dfrac{{250}}{{12}} = 2.8\Omega \]
Hence, the current and resistance are \[12A\]and \[2.8\Omega \].

Additional information:
The device which allows us to introduce a controlled amount of resistance into an electrical circuit is termed a resistor. The most important and also commonly used components in an electronic circuit are the resistors. The ease at which the electrons will allow the electricity to flow through it’s called resistance.

Note: Electric current is measured through a device named an ammeter. Materials that supply very low resistance are named conductors while materials that supply high resistance are called insulators. Higher is the resistance lower is the flow of current. Resistance is dependent on the kind of material and its dimensions.