Question

Define 1 watt.

Answer 1

HINT: 1Watt is the SI unit of power. Define the basic definition of what power is and describe it in terms of units of the basic physical quantities used in order to provide one watt. The basic units of 1 watt is equivalent to $1\dfrac{kg{{m}^{2}}}{{{s}^{3}}}$.

Complete step by step answer:
Watt, denoted by W, is a unit of power. In the International System of Units (SI) it is defined as an amount of 1 Joule energy used per sec, and is used to quantify the rate of energy transfer with respect to time. In SI base units, the watt is described as kg m2 s-3. The watt is named after James Watt, an 18th-century Scottish inventor.

Work is the ratio of energy used to the time taken for the process.

In terms of force, the energy of a body is the force acted on it times the displacement travelled. When an object's velocity is held constant at one meter per second against a constant opposing force of one newton, the rate at which work is done is one watt. It is described in the equation below.

$\begin{align}
  & 1J=1N\times 1m \\
 & \Rightarrow 1W=\dfrac{1J}{1s}=\dfrac{1N\times 1m}{1s}=1N\times 1m/s \\
\end{align}$

Power P, in terms of electricity, is associated with the current I and the voltage V in the circuit. Power in a circuit is given as current times voltage. Shown in the following formula:

$\begin{align}
  & P=I\times V \\
 & 1W=1A\times 1V \\
\end{align}$ Where, A is ampere, the unit of current.

Therefore, one watt is the power generated in a part of the electrical system when a potential difference of 1V is created when a current of 1A flows through it.

NOTE: The terms power and energy are frequently confused. Power is the rate at which energy is generated or consumed and hence is measured in units’ watts that represent energy per unit time. For example, when a light bulb with a power rating of 100W is turned on for one hour, the energy used is 100 watt hours (Wh), 0.1 kilowatt hour, or 360 kJ. This same amount of energy would light a 40-watt bulb for 2.5 hours or a 50-watt bulb for 2 hours. So, don’t confuse yourself between Power and Energy.