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The Difference Between
Ever wanted to know the difference between a boysenberry and a blueberry? socialism and communism? Windows and Linux? Look no further. This category answers your questions about 'The Differences Between...'
57,566 Questions
What is the difference between pleasing physical appearance and pleasing personality?
Main difference between Pleasing Physical Appearance and Pleasing Personality is that : Pleasing Physical Apperance is just due to the cloths, accessories or make up that you wear. But Pleasing Personality is Combination of both Physical appearance and Internal Personality Traits which brighten your looks, makes you enthusiastic and helps you portray a more confident picture of yours. The way you carry yourself, communication skills, cheerfulness, sense of humor etc. Namrta Mohan
Why is it difficult to define life?
Life is difficult to define because it encompasses a wide range of characteristics that are constantly evolving and vary across different forms of life. Additionally, the boundary between living and non-living entities is not always clear-cut, leading to ambiguity in defining life. Furthermore, the emergence of new discoveries and technologies continuously challenges traditional definitions of life.
Ground-dependent antennae refer to antennas that require a physical connection to the ground in order to function optimally. These antennas rely on the ground plane to radiate or receive radio signals efficiently. Ground-dependent antennas are commonly used in mobile communication devices and radio systems where a connection to the ground plane can be established.
How would brackish water taste?
Brackish water typically has a salty or slightly briny taste due to its mix of fresh and saltwater. The taste can vary depending on the ratio of saltwater to freshwater in the mixture.
How does a Potential Relay Work?
I am going to post an article published in 2006 by John Tomczyk of Ferris State University, Big Rapids, Mich. I cannot improve on his description.
The Potential Start Relay
Figure 1
This month's article will cover theory and operation of potential starting relays. The article that will appear in the Aug. 7 issue will cover potential relay ratings and specifications along with systematic troubleshooting.
Potential or voltage starting relays are used with single-phase capacitor-start/capacitor-run motors, which need relatively high starting torque. Their main function is to assist in starting the motor. These starting relays consist of a high-resistance coil and a set of normally closed contacts. The coil is wired between terminals 2 and 5, with the contacts between terminal 1 and 2. Terminals 4 and 6 are used for capacitor and/or condenser fan connections and have no electrical significance to the starting relay itself (Figure 1). Terminals 4 and 6 are sometimes referred to as dummy terminals and are simply used for wire connections.
Fig. 2 shows how a potential starting relay is wired to a capacitor-start/capacitor-run compressor motor. Note that the relay coil is wired in parallel (across) the start winding. The normally closed contacts are wired in series with the start winding and the start capacitor.
OPERATIONWhen the power is applied through the cycling control, both the run and start windings are energized. The start and run capacitors provide the phase shift for starting torque because of their capacitance adding when wired in parallel.In fact, both capacitors are wired in series with the start winding and in parallel with the run winding. The run capacitor also limits the current that will pass through the start winding when the motor is running, since they are wired in series. The run capacitor also provides running torque when the motor is up and running.
The operation of the potential starting relay is based on the increase in back electromotive force (back EMF) or a bucking voltage that is generated across the start winding as the motor increases in speed. The large metal mass of the motor's rotor turning at high speeds with motor windings in close proximity has a voltage generating effect (Figure 3). This generated back EMF opposes line voltage and can be measured across the start winding or across the coil of the potential relay at terminals 2 and 5. The back EMF is usually a higher voltage than the line voltage and can be in the 400-V range. All motors have different magnitudes of back EMF.
Figure 2
The back EMF voltage generated across the start winding causes a small current to flow in the start winding and in the potential relay coil since they are in the same circuit. When the back EMF has built up to a high enough value, referred to as pick-up voltage, the contacts between terminals 1 and 2 will be picked-up opened. This will take the start capacitor out of the circuit.
The pickup voltage usually occurs when the motor has reached about 3/4 speed. The start winding is still in the back EMF circuit keeping the relay's coil energized while the motor is running at full speed.
When the cycling control opens, line voltage power is taken away from the motor. The motor's rotor decreases in speed, thus the back EMF generated across the start winding decreases in magnitude. The relay now sees a lowering back EMF and no longer can generate enough magnetism in its iron core to keep contacts 1 and 2 open.
Figure 3
The contacts thus return to their original normally closed position by spring power as the motor coasts to a stop. With the start capacitor out of the circuit, the motor now becomes a permanent split capacitance (PSC) motor in the running mode only.
John Tomczyk is a professor of HVACR at Ferris State University, Big Rapids, Mich. He can be reached by e-mail at tomczykj@tucker-usa.com.
Publication date: 07/03/2006
Single-phase voltage and frequency
Countries in Europe and in many other areas of the world use a standard mains supply voltage for households and businesses of between 220 and 240 volts for lighting as well as for high-powered appliances. This is twice that of the voltage used for ordinary lighting and low-power appliances in US, Canada and most of the Americas, and also Japan. In those countries, and others using the same power distribution system, the standard mains supply voltage for low-power appliances is between 115 and 127 volts.
Note that currently all new American buildings in fact get 240 volts split into two 120 volts "hot" wires (often called "legs") with a common neutral wire. Major appliances, such as virtually all drying machines and ovens, are now connected to 240 volts.
The mains frequency in Europe and other 230 Volt areas is 50 Hz (Cycles per second) compared to 60 Hz in US, Canada and other 120/240 Volt areas. Some 60 Hz appliances will work fine but others with simple motors will run too slow on the lower frequency of 50 Hz. Similarly, some 50 Hz appliances will work fine but others with simple motors will run too fast on the higher frequency of 60 Hz.
However the most important difference is how the Neutral wire is connected:
240 volt 50 Hz service
A 240 volt 50 Hz appliance can have up to 3 wires altogether:
- one single 240 volt "live" or "hot" wire;
- a neutral wire;
- a safety "earth" or "ground" wire but this is not required if the appliance is of the type known as "double insulated".
The hot wire feeds alternating voltage from the power station to the load and, because the voltage is alternating, the load draws an alternating current. Then the neutral wire returns the current to the power station to complete the circuit.
240 volts 60 Hz service
An appliance that is designed to be connected to strictly 240 volts 60 Hz is connected with only a two wire cable plus a safety ground wire. (For example 240 volt 60 Hz base board heaters use that.)
The only time a cable with three wires plus safety ground is used is if 120/240 volts is needed in the equipment. (For example kitchen ranges or washing machines which have time clocks or programmers that require only a 120 volt feed.)
Thus an appliance designed to run on a 240/120 volt 60 Hz supply can have up to 4 wires altogether:
- two 120 volt 60 Hz live "hot legs" which run in opposing phase to one another: when one hot leg goes "+" (120 volts positive) the other leg goes "-" (120 volts negative);
- a neutral wired as a "central" common current return conductor:
- a safety "ground" wire but this is not required if the appliance is of the type known as "double insulated".
One of the two hot wires feeds a 120 volt alternating voltage from the power station to the 120 volt load - the clock or programmer - and, because the voltage is alternating, that load draws an alternating current. Then the neutral wire returns the current to the power station to complete the circuit.
Important conclusion
There is a 240 volt voltage difference between the neutral and the hot conductor in the 50 Hz system and only a 120 volt voltage difference between the neutral and each of the hot conductors in the 60 Hz system.
That is why an appliance designed to be connected onto the 50 Hz system cannot be used safely on the 60 Hz system without first having a proper technical inspection done, followed by any necessary modification work done to ensure that the appliance can be operated safely because, in the main breaker box, at the point where the 60 Hz "neutral" gets connected to the ground, this difference will cause serious problems!
A licensed electrician or electrical engineer would be able to consider whether or not a particular large appliance, that was manufactured to work on 50 Hz-only, could be modified to run safely at the higher 60 Hz frequency. However it won't usually be worth the expense of doing the work because it would be more cost-effective to buy (new or secondhand) an equivalent large appliance designed to work on 60 Hz.
The system of three-phase alternating current electrical generation and distribution was invented by a nineteenth century creative genius named Nicola Tesla. He made many careful calculations and measurements and found out that 60 Hz (Hertz, cycles per second) was the best frequency for alternating current (AC) power generating. He preferred 240 volts, which put him at odds with Thomas Edison, whose direct current (DC) systems were 110 volts. Perhaps Edison had a useful point in the safety factor of the lower voltage, but DC couldn't provide the power to a distance that AC could.
When the German company AEG built the first European generating facility, its engineers decided to fix the frequency at 50 Hz, because the number 60 didn't fit the metric standard unit sequence (1,2,5). At that time, AEG had a virtual monopoly and their standard spread to the rest of the continent. In Britain, differing frequencies proliferated, and only after World War II was the 50-cycle standard established.
However that might have been a mistake! Not only is 50 Hz 20% less effective in generation, it is 10 - 15% less efficient in transmission and requires up to 30% larger windings and magnetic core materials in transformer construction. Electric motors are much less efficient at the lower frequency, and must also be made more robust to handle the electrical losses and the extra heat generated. Today, only a handful of countries (Antigua, Guyana, Peru, the Philippines, South Korea and the Leeward Islands) follow Tesla's advice and use the 60 Hz frequency together with a voltage of 220 - 240 V.
Originally Europe was 120 V too, just like Japan and the US today. It has been deemed necessary to increase voltage to get more power with less losses and voltage drop from the same copper wire diameter. At the time the US also wanted to change but because of the cost involved to replace all electric appliances, they decided not to. At the time (1950s-1960s) the average US household already had a fridge, a washing-machine, etc., but not in Europe.
The end result is that now it may seem, to some people, that the US has not evolved from the 1950s and 1960s, and still copes with problems as light bulbs that burn out rather quickly when they are close to the transformer (too high a voltage), or just the other way round: not enough voltage at the end of the line. (115 to 127 volt spread!).
For more information see the answers to the Related Questions shown below.
If you are interested to know what what the different standard mains voltages and frequencies are around the world - and what the various plugs look like - the Related Link shown below has all the details.
Is activation energy for thermal and photochemical reactions same?
The definition of the activation energy is exactly the same -- the thermodynamic energy barrier that the reactant must pass over to convert to products.
The difference between a thermal and a photochemical reaction is only where the reactants get the energy to get over this barrier. In a thermal reaction, that energy is given by the temperature, and is carried in excited rotational modes, higher kinetic energies and if hot enough, excited vibrational states. In a photochemical reaction, the activation energy is provided by photons, usually in the form of electronic excited states, but could also be vibrational or rotational. The concept of the activation barrier is identical in both cases.
You will have to purchase a voltage converter that converts 220 volts to 110 volts. They are fairly inexpensive. Do not try to run your 110 volt appliances on 220 volts without a converter because you will damage them and could cause a fire.
What is the difference between ccfl and eefl?
CCFL (cold cathode fluorescent lamp) is different from EEFL (external electrode fluorescent lamp) in that the glass tube of the CCFL contains a small wire electrode that conducts the voltage to excite the gasses in the tube. The glass tube is molded around the electrode and that junction creates a possible point for the gasses to escape and the lamp to fail. EEFL is a completely sealed glass tube with a metal cap or conductive paint on the end acting as the electrode. When the proper voltage is applied to the external electrode, a capacitive connection is established between the electrode and the gasses within the tube and the lamp illuminates. Because the electrodes in CCFL's are in direct contact with the rare gasses, CCFL's run warmer than the EEFL's which are completely cool.
What is the difference of non reactive from negative result in serology?
A negative result in serology means that no specific antibodies or antigens were detected in the sample. Non-reactive, on the other hand, typically refers to the absence of a reaction during a test. In essence, a negative result indicates the absence of the specific substance being tested for, while non-reactive suggests no reaction occurred during testing.
A compound radical is a group of atoms that act as a single atom in a chemical reaction, often staying together as a unit. It combines with other atoms to form molecules, similar to how an individual atom would. A common example is the sulfate radical (SO4).
What is the difference between MDF and particleboard?
MDF uses a finer particle than particleboard. The result is a board that machines better ( more evenly) and has a nicer finish surface whereas particle board is used more in underlayment situations where the board will be hidden.
What is the permanant solution for hypothyriod?
The permanent solution for hypothyroidism is typically lifelong thyroid hormone replacement therapy. This involves taking synthetic hormones to make up for the lack of thyroid hormone production by the thyroid gland. Regular monitoring by a healthcare provider is necessary to adjust the dosage as needed.
Work = force x distance.
Work is calculated in Joules (J)
Force is calculated in Newtons (N)
Distance is calculated in the metric or customary system (m., ft., mi., in. etc)
Differences and similarities between gravitational force and electrostatic force?
Similarities:
inverse square law for strength of force
both r central forces
both are conservative forces
both follow principle of superposition
Differences
gravity attracts electric force
electric force can change direction
electrostatic force depends on interviening medium
Creatine as a by product of methamphetimine?
While creatine is not a by-product of methamphetamine production, some individuals may mistakenly consider it to be due to the appearance of creatine in certain high-energy beverages mixed with methamphetamine. These beverages are often consumed by individuals looking for a boost in physical performance while using methamphetamine. Creatine itself is a naturally occurring compound found in the body and in certain foods, commonly used as a supplement to improve athletic performance.
Is a lock a fitting or a fixture?
A lock is typically considered a fitting because it can be easily removed from a door or a piece of furniture without causing damage to the structure. Fixtures, on the other hand, are generally considered permanent additions to a property.
What are the differences between physical and chemical changes?
Well, a physical change is a change in how something looks/ seems. For example, a metal box would go through a physical change if pounded on with a hammer. A chemical change is a change in molecular formula that you can NOT see. For example, there is CH2. If this became CH for some reason, it would be a change in the formula structure, a change yuo cannnot see.
What is the difference between mass and energy?
well mass and energy are like two sides of a coin. According to Albert
Einstein's Mass Energy equation, mass can be converted to energy which is given by the equation E= M*C^2.
Mass is anything that has weight and occupies space whereas Energy is the ability to do work or to put matter into motion. (Delmar Cengage Learning)
What is the difference between excited hydrogen atom and any other atom?
Hydrogen atom = 1 proton 1 electron Hydrogen's 1 electron occupies the lowest energy level, 1s orbital. The atom is therefore in its "ground state". When a photon of correct frequency "collides" with a electron in hydrogen's 1s orbital the energy contained in the photon is transferred to the electron. The electron then gets added energy, so it is at a higher energy state. When it reaches this higher energy state the electron jumps to the next energy level and there it starts its new orbit. Hydrogen atom is now "excited" For any other atoms it is the same thing because all atoms can undergo excitation. The only difference between hydrogen's 1 electron and other atom's many electrons is WHICH ELECTRON will be "excited"
I swallowed some anti-bacterial foaming soap. Is this bad?
The active ingredient in antibacterial soap, triclosan, is not toxic. It is used in soap, deodorant, mouthwash, etc.
Be more careful. Things that taste yucky are probably never good for you to consume often.
Ecsept Veggies!
Dexamethasone is sparingly soluble in water but freely soluble in methanol, ethanol, and chloroform. Solubility may vary depending on the specific salt form or preparation of dexamethasone being used.
What is the difference between radiowaves and microwaves?
The frequency spectrum in which they operate. Microwaves are generally in the ultra high and super high and extremely high frequency bands, e.g., UHF 300 to 3000 MHz and 3000 to 30000 MHz and 30 to 300 GHz, respectively. Thus, radio waves and microwaves can be used to transmit information, as such, they are synonomous. However, radio waves can be generated throughout the electromagnetic spectrum from near 0 Hz to 300 GHz, but are generally considered to be in the frequencies ranges below the infared bands. Microwave is a term used to express electromagnetic energy at higher frequencies. http://en.wikipedia.org/wiki/Radio_waves http://en.wikipedia.org/wiki/Radio_frequency http://imagine.gsfc.nasa.gov/docs/science/know_l1/emspectrum.html http://en.wikipedia.org/wiki/Microwaves
There is no such that as "millipore-q". A company named Millipore manufactures a high purity water system called the "Mill-Q". If produces pure water for laboratory uses. The millipore systems are extremely expensive and very expensive to operate. Barnstead also makes pure water systems at significant savings
What is the difference between sterilization and canning?
Sterilization is a process of killing all microorganisms in a specific environment, such as in medical equipment or laboratory materials, whereas canning is a method of preserving food by heating it in airtight containers to kill bacteria and prevent spoilage. Sterilization is typically done at higher temperatures for longer periods to achieve complete elimination of microorganisms, while canning focuses on preserving food for consumption at a later time.
