PHYS1001

about 0.6 volts

A typical silicon p-n junction diode produces about how much energy?

~10^10 m

A typical size of an atom?

Devices can also be charged wirelessly by induction, without the need for exposed electric contacts. The effect is like a transformer's.

How can electronic devices charged wirelessly?

The magnetic field strength of an electromagnet can be increased by simply increasing the electric current through the coil and the number of turns in the coil.

How can the magnetic field strength of an electromagnetic increased?

A laser printer uses a computer output to program the intensity of a laser beam onto a selenium- coated drum.

How do laser printers work?

They use electrostatic attraction to print an image.

How do photocopiers and laser printers print an image.

A computer's random-access memory (RAM) uses tiny capacitors to store the digital "ones" and "zeroes" that make up data. A charged capacitor represents a "one", and an uncharged capacitor a "zero". For a billion or more capacitors to fit on a single semiconductor chip they must be very small.

How does a computer's random-access memory store information?

A heat engine gains heat from a reservoir of higher temperature, increasing the engine's internal energy, converts into mechanical work, remaining energy expelled as heat to a sink.

How does a heat engine work?

The operating principle of a heat pump is just the reverse of a heat engine. Pump heat out of the cooler environment. Ex: Refrigerators, Ari-cons Second law: it is impossible for any process to have as its sole result the transfer of heat from a cooler to a hotter body. Clausius statement = Kelvin-Planck statement

How does a heat pump operate?

Ultra-intense pulses of laser light are used to heat and compress a tiny sphere containing deuterium and tritium so that fusion occurs.

How does inertial confinement fusion work?

It prevents the plasma from touching the walls of the container where it would quickly cool off.

How does magnetic confinement fusion work?

The decreased mass that results from two hydrogen combining to become helium is converted to energy.

How does nuclear fusion generate energy?

Mass and energy are equivalent. E = mc^2 A small mass corresponds to an enormous quantity of energy.

How is Mass-Energy Equivalence explained?

By gas centrifuge. Heavier U-238 gravitate to the outside, and gas containing the lighter U-235 is extracted from the center.

How is Uranium-isotope separation done nowadays?

Any two conductors separated by an insulator (or a vacuum) form a capacitor.

How is a capacitor formed?

The magnetic field is changing about the primary coil, and this changing field extends into the secondary coil. When the magnetic field is no longer changing, no voltage is induced in the secondary coil.

How is a voltage or an electromotive force induced in the secondary coil?

Neutrons can cause the fission of additional uranium atoms, releasing more neutrons, cause more fissions.

How is chain reaction carried out during nuclear fission?

The heated water is tapped to provide steam for driving electric generators. Dry-rock geothermal power, water is pumped into hot fractured rock, turned into steam and pumped back to surface.

How is geothermal power produced?

Fusion reactions does not produce radioactive fragments.

How is nuclear fusion reactors preferred?

Photovoltaic cells, also called solar cells.

How is solar power converted to usable energy?

The nuclear reactor is housed within a dome-shaped containment.

How is the release of radioactive isotopes prevented in the event of an accident?

200,000,000 eV

How much energy is released for a typical fission reaction?

0.03%

Human beings are ______ percent of the universe.

Light is an electromagnetic wave.

Maxwell discovered?

1. Object in motion stay in motion unless acted on by outside force. 2. Force is mass times acceleration. 3. For every action there is an equal and opposite reaction.

Newton's three laws of motion are:

Nuclear forces

The Sun is burning for billions of years because?

Kinetic energy of the fission fragments and a smaller amount of energy is that of gamma radiation.

The energy of fission is mainly in the form of?

additive manufacturing. An ink-jet printer precisely spits a series of blobs of ink to produce images, while a 3-D printer deposits blobs of material to make solid objects.

3-dimensional (3-D) printing is also known as ?

Mechanics, Thermophysics, Optics, Electricity, Magnetism

5 Major areas of Physics?

Modern civilization

According to Prof. Kaku, the history of physics is the history of?

Critical mass, for masses greater than a certain amount.

An explosion of enormous magnitude may occur due to nuclear fission at what stage?

positive

Done in the dark, is the placing of a uniform __________ electric charge on the drum's selenium layer by a charged roller or rod.

10 million times

Fissioning of a single uranium nucleus releases _______ times as much energy as the combustion of carbon to produce a single carbon dioxide molecule.

Strong Weak or zero

For laser printers, the intensity of the beam is _________ for a point that is meant to be bright or white, while ____________ for points that are meant to come out dark.

equal

If the primary and secondary coils have the same number of turns, then the input and output alternating voltages will be ?

Lower. The voltage is said to be stepped down.

If the secondary coil has less turns than the primary, the alternating voltage produced in the secondary coil will be _______ than that in the primary.

Higher. The voltage is said to be stepped up.

If the secondary coil has more turns than the primary, the alternating voltage produced in the secondary coil will be _______ than that in the primary.

Drum

In a photocopier, lenses and mirrors focus an image of the original sheet of paper onto the ______.

negative

In photocopiers, a fine dark powder known as toner is given a ___________ electric charge, and is brushed on the drum as it rotates.

Fast neutrons are captured by U-238, slowed neutrons are readily captured by U-235 and enables a chain reaction.

Is fast neutron or slow neutron more easily absorbed by U-235 to cause fission in another U-235 atom?

No. Like electricity, it needs an energy source and is a way of storing and transporting that energy.

Is hydrogen a source of energy?

Yes, the energy of wind can be used to turn turbine generators within specially equipped windmills.

Is wind power a form of solar power?

Energy cannot be created nor destroyed, transformation of energy.

Law of conservation of energy?

By doing work, heat is taken from a lower-temperature region, and a greater amount of heat is exhausted at a higher temperature.

Mechanism of a refrigerator?

The refrigerator box becomes a room or an entire building. The evaporator coils are inside, the condenser is outside, and fans circulate air through these.

Mechanism of air conditioners?

A four-cycle gasoline internal combustion engine. Stirling Engine - use temperature difference

More examples of heat engines...

matter, energy and the relationships between them

Physics is defined as the study of?

Gravitational potential energy.

The potential energy due to elevated positions is called?

10^-9

The sun emits enormous amounts of energy, about _ reach the earth.

Photovoltaic cells are p-n junction diodes- crystal wafers produced the same way that semiconductors are made for computers.

What are Photovoltaic cells?

Heat engine is any device that uses heat as input and provides mechanical work as output. Examples of heat engines include steam engines, internal combustion engines, jet engines.

What are heat engines? What are some examples of heat engines?

1. Plentiful electricity 2. Save natural gas 3. Eliminate sulfor oxide, carbon dioxide emission

What are some benefits of fission power?

1. Problem of storing radioactive wastes 2. Production of plutonium 3. Release of radioactive materials

What are some drawbacks of nuclear fission power?

The supercapacitor bus is an electric bus powered by supercapacitor technology. As it does not rely on chemical reactions to store electrical energy, the supercapacitor bus is more environmentally friendly than a battery-based electric bus.

What are supercapacitor buses?

They are made of a neutron-absorbing material, usually cadmium or boron.

What are the control rods to control the reaction rate made of?

1. nuclear fuel 2. control rods 3. moderator 4. fluid coolant

What are the four components of today's fission reactors?

1. Observation 2. Experiment 3. Reasoning 4. Theorization 5. Prediction

What are the major steps of physics methodology?

Inertial confinement fusion and magnetic confinement fusion.

What are the two main techniques that are being tried to heat deuterium and tritium and to hold them together long enough for fusion to occur?

Potential and Kinetic energy

What are the two most common forms of mechanical energy?

Instead of opening or closing a switch to produce the change of magnetic field, an alternating current (ac) can be used.

What can be used to power the primary circuit in a practical transformer.

Faraday's law states that the induced voltage in a coil is proportional to the product of its number of loops, the cross- sectional area of each loop, and the rate at which the magnetic field changes within the loops.

What does Faraday's law state?

Lenz's law states that an induced current or voltage always tends to oppose or cancel out the change that caused it. (Lenz's law can be derived from Faraday's law and is often easier to use.)

What does Lenz's law state?

A fuel cell converts the chemical energy of a fuel to electrical energy.

What does a fuel cell do?

The capacitance is a measure of the ability of a capacitor to store energy.

What does capacitance measure?

Energy (Joules)

What enables an object to do work?

Release energy

What happens when matter meets anti-matter?

A moving wire in a magnetic field generates electric current.

What is Faraday's law about?

Tidal power

What is a clean source of energy generated from the rotational energy of our planet?

Electrolysis - electrically splitting water into its constituent parts.

What is a cleaner method to obtain Hydrogen that does not produce greenhouse gases?

The unavoidable production of carbon dioxide, a greenhouse gas.

What is a downside to hydrogen separation from hydrocarbon compounds?

A current-carrying coil of wire is an electromagnet.

What is an electromagnet?

Inducing voltage by changing the magnetic field in loops of wire. Voltage is induced by the relative motion between a wire and a magnetic field.

What is electromagnetic induction?

Electrostatics is the study of interactions between electric charges that are at rest.

What is electrostatics?

Energy of motion.

What is kinetic energy?

It is the opposite of nuclear fission where energy is gained as light nuclei fuse or combine.

What is nuclear fusion?

Tokamak - form a magnetic doughnut.

What is one of the most promising magnetic confinement schemes?

The energy that is stored and held in readiness by virtue of its position.

What is potential energy?

A neutron is absorbed, and the resultant fission process may produce many different combinations of smaller nuclei.

What is required by a uranium nucleus to supply enough energy to cause elongation for nuclear fission.

Fission - 0.1% Fusion - 0.7%

What is the amount of matter that is converted to energy in fission and fusion reactions?

1,400 joules 1.4 kW

What is the amount of radiant energy received each second over each square meter at right angles to the Sun's rays at the top of the atmosphere?

About 30 x 10^-15 farads

What is the capacitance of each capacitor of computer's RAM?

U (internal energy) = Q (heat added to the system) - W (work done by the system)

What is the first law of thermodynamics?

Plasma - an electrified gas, with electrons and ions, electrically neutral.

What is the fourth phase of matter in addition to solids, liquids, and gases?

The internal energy of a system is the sum of the kinetic energies of all of its constituent particles. plus the sum of all the potential energies of interaction among these particles.

What is the internal energy of a system?

Hydrogen. Hydrogen can be produced from natural gas, where high temperatures and pressures separate hydrogen from hydrocarbon molecules.

What is the least polluting fuel?

The greater force is nuclear. Critical deformation with elongation. The greater force is now electrical. The nucleus separates.

What is the mechanism behind nuclear fission.

Power sheets

What is the newer technology that is replacing panels composed of photovoltaic cells?

It means to be an electrical non-conductor in the dark, but a conductor when exposed to light.

What is the property called photoconductivity?

It states that it is impossible for any system to undergo a process in which it absorbs heat from a reservoir at a single temperature and converts the heat completely into mechanical work, with the system ending in the same state in which it began. Kelvin-Plank statement

What is the second law of thermodynamics?

The Sun. Photosynthesis - the process by which plants store solar energy.

What is the source of practically all our energy?

The nuclear fuel is primarily U-238 plus about 3-5% U-235. Explosion is not possible.

What is the typical composition of nuclear fuel?

Work equals change in kinetic energy. Friction also acts on the object, then the change of kinetic energy is equal to the work done by the net force.

What is the work-energy theorem?

Fusion brought about by high temperatures. More than 100 million degrees celsius.

What is thermonuclear fusion?

Graphite (C) and deuterium (H-2)

What is used to slow the neutrons? (moderator)

Why do we have energy on the earth?

What phenomena does e=mc^2 explain?

Unified field theory

What was Einstein's unresolved problem when he died?

Shrank

When balloons are immersed in liquid nitrogen, they become:

hard

When immersed in liquid nitrogen, banana becomes?

Hydrogen cells are more costly. Difficult to store, transport, and use safely. Not available in free state.

Why aren't hydrogen fuel cells widespread nowadays?

The U-235 isotope makes up only 0.7% of the uranium. The U-238 does not undergo fission when it absorbs neutrons created by fission of U-235.

Why don't chain reactions occur in naturally occurring uranium ore deposits?