Question

Relation between the power$(P)$ consumed by a device, its resistance $(R)$ and voltage$(V)$ across it.
A) $P = VR$
B) $P = \dfrac{{{V^2}}}{R}$
C) $P = \dfrac{V}{t}$
D) None

Answer 1

Just like electricity, we hear a lot about the word force. It has a broad variety of meanings in daily life. But it has a very unique importance in physics. It is an indication of how quickly (or equally when energy is transferred) work is done. One of the basic abilities of early engineers to build steam engines that were the driving force behind the industrial revolution was the capacity to quantify power accurately. The best way to use energy resources that drive the modern world remains essential for understanding.

Complete step by step answer:
Power is the rate of supply or consumption of electricity and voltage that requires the supply / consumption of energy. The higher the stress, the more strength there will be. If the quantity of electricity available is limited, such as that of a charging battery, greater electricity may be consumed better because the voltage is greater.
The formula for power is
$P = VI$
Where $V$ is voltage and $I$ is current.
Current is given by $\dfrac {V} {R}$,
Therefore,
$P = \dfrac{{{V^2}}} {R}$
Therefore, correct option is B

Note: Peak energy is the greatest output on a given device for a span of time that instantaneous electricity may provide. Automotive motors and stereo systems are examples of systems which are much higher than their average capacity to deliver peak power. However, this control can typically only be sustained for a limited period of time to prevent injury. Nevertheless a high peak power in these systems might be more important than a high average power to push or listen.