# What Is Power Formula?

## What is the formula of power Class 10?

The electric power is given by P = VI.

Where V is the potential difference, I is the electric current and P is the electric power..

## Why is the power factor negative?

A negative power factor occurs when the device (which is normally the load) generates power, which then flows back towards the source. In an electric power system, a load with a low power factor draws more current than a load with a high power factor for the same amount of useful power transferred.

## What is the common formula for work?

Work can be calculated with the equation: Work = Force × Distance. The SI unit for work is the joule (J), or Newton • meter (N • m). One joule equals the amount of work that is done when 1 N of force moves an object over a distance of 1 m.

## What is the current formula?

Current is usually denoted by the symbol I. Ohm’s law relates the current flowing through a conductor to the voltage V and resistance R; that is, V = IR. An alternative statement of Ohm’s law is I = V/R.

## What is the electricity power?

Electric power is the rate, per unit time, at which electrical energy is transferred by an electric circuit. The SI unit of power is the watt, one joule per second. … It is usually supplied to businesses and homes (as domestic mains electricity) by the electric power industry through an electric power grid.

## What is the efficiency formula?

Efficiency is often measured as the ratio of useful output to total input, which can be expressed with the mathematical formula r=P/C, where P is the amount of useful output (“product”) produced per the amount C (“cost”) of resources consumed.

## What is the unit of current *?

AmpereStandard Electrical Units of MeasureElectrical ParameterMeasuring UnitDescriptionCurrentAmpereUnit of Electrical Current I = V ÷ RResistanceOhmUnit of DC Resistance R = V ÷ IConductanceSiemenReciprocal of Resistance G = 1 ÷ RCapacitanceFaradUnit of Capacitance C = Q ÷ V6 more rows

## What is negative electrical power?

Power is a signed quantity; negative power just represents power flowing in the opposite direction from positive power. … This increases the potential energy of the electric charges, so electric power flows out of the component into the circuit.

## How do you calculate wasted power?

It is computed Input Power minus output power. For example you have a PC power supply for your computer. You can measure the input power by taking AC measurements, say 1A at 120VAC = 120 Watts. The wasted power is 120W – 102 W = 18 W.

## Is voltage a power?

Voltage is the pressure from an electrical circuit’s power source that pushes charged electrons (current) through a conducting loop, enabling them to do work such as illuminating a light. In brief, voltage = pressure, and it is measured in volts (V). … Current returns to the power source.

## What is work formula?

Work is done when a force that is applied to an object moves that object. The work is calculated by multiplying the force by the amount of movement of an object (W = F * d).

## Can power be negative?

The sign of power is just a matter of definition. Energy can increase or decrease, but the energy itself cannot be negative. … As you said, power is just the time rate of change of energy, so it can be negative. But energy is only positive.

## What is negative voltage?

Negative voltage in a circuit is voltage that is more negative in polarity than the ground of the circuit. … The second circuit is the exact opposite, where the positive end of the voltage source is connected to ground, while the negative end is not.

## What is power used for?

Power is one of the key units in many electronic circuits. It can be used to indicate the level of heat dissipated in a unit or even an individual component, it can be used to define the power consumed, and it can also be used to define the amount of power generated by the system to pass on to the next item.

## What is power and its type?

As you can see, there are many different types of personal power. Personal power is the ability to control the environment around you. This can be accomplished through the five different types of power: reward power, coercive power, legitimate power, expert power, and referent power.

## How do you calculate power?

Power is a measure of the amount of work that can be done in a given amount of time. Power equals work (J) divided by time (s). The SI unit for power is the watt (W), which equals 1 joule of work per second (J/s). Power may be measured in a unit called the horsepower.

## What is the formula for electrical power?

In other words, Energy = power x time and Power = voltage x current. Therefore electrical power is related to energy and the unit given for electrical energy is the watt-seconds or joules. Electrical power can also be defined as the rate of by which energy is transferred.

## What is thermal efficiency formula?

So, for a boiler that produces 210 kW (or 700,000 BTU/h) output for each 300 kW (or 1,000,000 BTU/h) heat-equivalent input, its thermal efficiency is 210/300 = 0.70, or 70%. This means that 30% of the energy is lost to the environment. An electric resistance heater has a thermal efficiency close to 100%.

## What is D work formula?

d = distance (m) θ = the angle between the force direction and movement direction. Work Formula Questions: 1) A tractor pulled a wagon full of hay a distance of 1000 m.

## How can I calculate weight?

Weight is a measure of the force of gravity pulling down on an object. It depends on the object’s mass and the acceleration due to gravity, which is 9.8 m/s2 on Earth. The formula for calculating weight is F = m × 9.8 m/s2, where F is the object’s weight in Newtons (N) and m is the object’s mass in kilograms.