Electrical Power

Yes, it is true

Is it true that in an electric circuit, electrical energy is continuously converted into other forms of energy?

thermal energy

When a current flows in a conductor, electrical energy is converted into ______________ within the conductor.

Power

The rate at which the work is done by force.

Or the rate at which the energy is transferred

Is measured in watts

A 60-W bulb

Among the 60 W bulb and 25?W bulb which bulb will glow brighter and will be warmer?

electrical energy

The heat and the light in the bulb is produced by the conversion of _________________.

Electrical field

________________ exists between the two potentials, which points from the higher potential to the lower potential

Electrical potential

The potential energy per charge

V = U/q

Mathematical representation of the Electrical potential

high, low, loses

The natural direction of the positive charge is from the ____ electrical potential to the ___ electrical potential where it _____ its potential energy.

low, high, work, gains

The direction of the motion of the positive charge to go from ___ electrical potential to ____ electrical potential requires ____. It _____ potential energy in this process.

gains, high, low

A negative charge _____ potential energy when it travels from ____ electrical potential to ___ electrical potential.

loses, low, high

A negative charge _____ its potential energy when it travels from ___ electrical potential to ____ electrical potential.

From higher potential to the lower potential

What’s the always known electrical fields direction when there is a potential difference across the conductor.

positive charge

For a ______________ the force exerted on it is in the direction of the electric field

negative charge

For a ______________ the force exerted on it is in the opposite direction of the electric field

F = ma = QE

Write an equation for the force exerted on the positive charge due to its electrical field.

This is the force which is necessary to keep the positive charge moving.

This force does not act to accelerate the charge through the entire distance because of the interactions of the charge with atoms and free electrons in the material. (Therefore no increase in the kinetic energy of the charge)

Charge will have the same vd which it had at its starting point

negative

When the positive charge moves in the direction of the electrical field, its change in potential difference will always be ________.

E = - ΔV/ΔL

Formula to find the electrical field that made the positive charge move, that resulted into a negative potential difference

W = FΔL = (QE)ΔL = Q(- ΔV/ΔL)*ΔL = -QΔV = -ΔU

The entire step-by-step derivation of the work done on that positive charge by the electrical field.

potential energy, average kinetic energy

The charge moves at a drift velocity, so the work done on the charge results in the loss of ________________ but the ______________________ remains constant.

The lost electrical potential energy, radiation

When the charge moves, the material through which it moves appears to have thermal energy from…

Results in an increase in the temperature, which is dissipated as _________

heat, heat and light

In a resistor, thermal energy is dissipated as ____, and in a light bulb as ______________

P = ΔU/Δt = QΔV/Δt = IV

The most flexible formula to find out the power. Write this formula with its derivation Basically the electric power gained or lost by any device

P = I^2 * R

Formula to find power. (Best used when you don’t know the voltage) Specifically used in the case of a resistor

P = V^2/R

Formula to find power. (Best used when you don’t know the current) Specifically used in the case of a resistor

This equation implies that lower the resistance is connected to a voltage source the greater the power it will deliver.

P = Fv

Formula which is used to find the power used in lifting the object at a constant speed

80%

Approximate efficiency of a 1-hp motor

90%

Approximate efficiency of a 100-hp motor

Fuse

A device that protects the circuit from currents that are too high.

It is basically a short piece of wire between two contacts.

It’s piece of wire under the tension has a low melting point.

They have a small time delay while the wire heats up and breaks.

Are not reusable.

Circuit breakers

Are also rated for maximum current and open to protect the circuit, they are much faster and are reusable.

Ground Fault Circuit Interrupter

Abbreviated as GFCI

Used commonly in bathrooms and kitchens

These outlets respond very quickly to changes in the current

These outlets open when there is a change in the magnetic field, which is produced by a current carrying conductor.

P = dE/dt

Equation that states derivative relationship with the Power and Energy.

E = ∫ (P) dt

Equation that states integral relationship with the Power and Energy.

E = Pt

Equation used to find the energy if the power is delivered at a constant rate.

(kW•h)

The energy unit on electricity bills

3.6×10^6 J

1 kW•h = ? Joules

20%, 40%

About ___ of a home’s use of energy goes to lighting, and the number for commercial establishments is closer to ___

15-W CFL, 4 times

A 60-W incandescent bulb can be replaced by ________, which has the same brightness and color. They are _______ more efficient than the incandescent lights.

CFL bulbs

A bent tube inside a globe or a spiral shaped tube (housed with argon and mercury vapor), all connected to a standard screw in base that fits standard incandescent light sockets

10 times, 5 times

CFLs last ________ longer than the incandescent bulbs. New white LEDs last _______ longer than the CFLs

Ballast

A built-in electronic component of a CFL boosts the voltage to start the bulb and then controls the current so the bulb runs safely and efficiently.

gas mixture, gas molecules, ultraviolet light, fluorescent coating

The ballast produces an electrical current which passes through the ___________ and excites the _____________, producing _________________, which in turn stimulates the ___________________ on the inside of the bulb.

Fluorescence

The emission of light by a substance that has absorbed light or other electromagnetic radiations.

LED

A special type of diode made of semiconducting materials infused with impurities in combinations and concentrations that enable the extra energy from the movement of the electrons during electrical excitation to be converted into visible light.

Commercial LEDs

Designed for the visible spectrum and are constructed from gallium doped with arsenic and phosphorus atoms.

Luminous flux

A measure of the total quantity of visible light emitted by a source

lumen (lm)

The SI derived unit of luminous flux which is used to measure the light outputs of the light sources

50,000 hours, 8000 hours, and 1200 hours

The total life span of an LED, CFL, and the incandescent

Neurotoxin

A poison which acts on the nervous system

800 lm

Light output of a 13-15W CFL bulb, or 6-8W LED, or 60W incandescent light bulb