Electrical Engineering

Armature current is the current flowing in a motor's armature.

The "armature" is another name for the coil (or coils) of wire which are on the motor's "rotor", which is the part that rotates inside its stator. (The "stator" is the fixed, non-rotating part of the motor.)

The resistance of a motor winding is expressed in

biomedical engineer questions with answers

1.The effective voltages of the incoming generator must be exactly equal to that of the others or of the bus bars connecting them.

2.The phase rotation or sequence of the running and incoming generators must be same.

3. The frequency should be same.

There are various measures that can be taken to reduce core losses. Lamination of the transformer core is believed to reduce core losses significantly.

'Nominal' means 'named'. So a 'nominal' voltage is the named voltage of a system. For example, when we talk about a 120-V or 240-V system, we are describing their nominal values, not their actual values which can change from moment to moment.

That is 366,300 ohms.

Stephen Gray was an English astronomer that experimented with static electricity and plasma glows.

The com is your common terminal also the negative terminal where the black probe is pluged in. normally used on meter with 3 or more connectors and only the red probe change position

The basic principle of a transducer:

A transducer which converts a physical quantity to the electrical quantity.

Eddy currents are currents induced in conductors to oppose the change in flux that generated them. It is caused when a conductor is exposed to a changing magnetic field due to relative motion of the field source and conductor, or due to variations of the field with time. This can cause a circulating flow of electrons, or a current, within the body of the conductor. These circulating eddies of current create induced magnetic fields that oppose the change of the original magnetic field due to Lenz's law, causing repulsive or drag forces between the conductor and the magnet. The stronger the applied magnetic field, or the greater the electrical conductivity of the conductor, or the faster the field that the conductor is exposed to changes, then the greater the currents that are developed and the greater the opposing field.

unity-gain frequency

can dc volts kill you? It is in relationship to the amount of time the body is conducting the milliamp current. With your DC static charge, once the potential voltage has equalized by grounding the current flow stops. On a 240 volt system the voltage remains constant thereby causing the current to continually flow through the body. If you have ever has an electrical shock you know the feeling.

the north pole magnet and straight rod present in the moter .the current flow in the rod and rod rotate on the magnetic force.And the moter run.

V=I*R OR

R=V/I OR

I=V/R

AT constant temperature

it has very high speed but no load

Clutter Improvement factor is defined, formally, as the ratio of output SCR to input SCR which works out to be a product of clutter attenuation and signal gain. It is a measure of a systems rejection capabilities of clutter power as a function of Doppler frequency.

Ohm's Law states that Voltage = Resistance (Ohms) * Current (Ampere).

So when you increase voltage, you increase current.

That is an open line.

Ultrasonics are sound waves with frequencies above 20khz.

GALTON WHISTLE

First they were produced by Galton.He called his Instrument the galton whistle.It consisted of a brass tube 2 mm in diameter and it was operated by blowing in a jet of high pressure gas.it consisted of a piston.on moving it the resonant cavity's length varied,on varying the length the resonant frequency too varied.Thus the resonant frequency depends on the length of the tube/pipe.But this could produce only up to 30khz.

MAGNETOSTRICTION METHOD

the main principle for this method is when a ferromagnetic rod made of material like iron or nickel is subjected to alternating magnetic field applied parallel to the rod,there will be a small elongation or contraction in its length.this change in length is proportional to the intensity of the magnetic field and nature of the ferromagnetic material.

so the length of the rod changes for each half cycle of the alternating current which means the frequency will be twice the frequency of alternating current..

when the natural frequency of the rod matches with the frequency of the alternating current resonance occurs and amplitude will be maximum and ultrasonic waves are produced.In this method frequencies up-to 300KHZ can be produced.

PIEZOELECTRIC OSCILLATOR

The main principle of this is the inverse piezoelectric effect..according to the piezoelectric effect,when one pair of opposite faces of a crystal like quartz is subjected to pressure the other pair of opposite faces will develop electric charges and if the pressure is replaced by tension then the charges will be reversed..the inverse of this effect is that if the pair of opposite faces are subjected to alternating voltages then the other pair of opposite faces varies in its dimensions,i.e. it expands or contracts periodically thus generating elastic waves.When the natural frequency of the crystal matches with the frequency of the alternating current,resonance occurs and ultrasonic waves are produced.In this method frequencies upto 500MHZ can be produced.

This seems like a question from an electrical course, and is probably best answered by referring to your course materials.

It's your test question, not ours, and there won't always be someone else to ask for the answer.

Earn your diploma.

A k ohm is a kiloohm and that is 1000 ohms.

it like this the total population divided by the total land area that is cultivated

or in simple TP/TLA

By Aobure Reeia