Electrical Engineering

Batteries in series makes the voltage additive. If the bulb is only rated at a specific voltage and you double the voltage the bulb will glow brighter but its life span will be shortened. Batteries in parallel will keep the voltage at the same level as a single battery but the endurance drain of the batteries will be doubled. Example, if a battery is drained of power, with a bulb being left on continuously, in one hour then two batteries in parallel would allow the bulb to glow for two hours before the batteries were drained of power.

The application of engineering knowledge to the development of medical products. The engineering disciplines involved range from the traditional engineering fields to software and genetic engineering. The field is broken up into a number of specialty areas as varied as the biological and engineering fields from which they spring.

Single bus is used in smaller, less important substations. A fault on the bus requires tripping of all lines into the bus. When higher redundancy is necessary, ring and breaker and 1/2 schemes are used. These are the three most common.

rms. dat means Vp-p will be 325V.

You reduce voltage in a DC circuit with a resistor. If the power demands are high, however, you may need a switching voltage regulator.

Voltage = resistance X current abbreviated,
V = C * R


If you halve the voltage of the current, then the other side of the equation must also be halved; therefore, you get:


(1/2)V=(1/2)(C*R)


which is the same as:


(1/2)V=(1/2)(C)(R)


which means that either the current or the resistance must be halved as well, and because the resistance stays the same, then the current is halved.

A transformer makes and collapses a magnetic Field inside 60 times a second for home power in North America, 50 times a second in Europe.

The building and collapsing of a magnetic field "Induces" a voltage in another transformer winding.

DC current only creates a stable magnetic field and this will not create or induce voltage in the other winding.

Normally covered in grade 5 science where I live.

A relay can be seen as a messenger. In electricity, a relay is a electromagnetic switch which closes or opens its contacts if its coil is energized by electricity. It can only handle small voltage or current typically 24vdc or 240vac.

The output of motors are only measured in horsepower in North America. Practically everywhere else, the output is measured in watts. The horsepower and the watt both measure exactly the same thing: power. The horsepower is simply the Imperial unit, whereas the watt is the SI unit. They are interchangeable.

1. Provides a high data rate.

2. cost of purchsing towers for transmission is pretty low.

3. small antennas are required.

4. No cables needed

5. Multiple channels available

6. Wide bandwidth

Every line has an upper limit and a lower limit on the frequency of signals it can carry. This limited range is called the bandwidth. The signals ranging within the upper limit & lower limit are called bandwidth signals.

Loads receive current independently of each other.

Typical applications; "the motor will have a limited amount of torque, lesser in value than what is needed for normal operation. Thus, is real world workings the unit will overload, stop, not work, trip OL.

The magnetization current imposes an upper limit on the voltage applied to a transformer core due to the ability of the respective spark gap to extinguish. If too much current supply is available the spark gap becomes overheated. This makes it unable to "switch-off" when the high or elevated supply current is flowing through it.

600 volts is five times the 120 volt primary, so the secondary winding must have 750 turns, which is five times as many turns as the 150 turns of the primary winding.

For an 'ideal' transformer operating at full load, the answer is yes. But, 'real' transformers are a little less than 100% efficient so, in practice, the input power will slightly exceed the output power. In most circumstances, for the purpose of calculating primary and secondary currents, we can assume 100% efficiency.

An electric generator converts mechanical energy to electric energy while a motor converts electric energy to mechanical. A generator can actually act as a motor if it losses whatever is making it spin (called "motoring"), which is usually a very bad thing. Motors may be used as generators as well, depending on their design.

Withstand Voltage :

The voltage which has to be applied to a test object under specified conditions in a withstand test is called the withstand voltage ( as per IS:731 and IS: 2099-19631 )

unfortunately i don't know the name of the book, I just know " page 405 , chapter 10 , High-voltage testing of electrical apparatus "

the book name is HIGH VOLTAGE ENGINEERING (2nd edition ) by Naidu, Kamaraju

The power dissipated by a diode is P = Vf x I watts, where Vf is the forward voltage drop on diode (typically 0.5 volts for silicon diode) and I is the current.

In an alternating current system, the voltage and current may or may not rise and fall at the same time. In resistive circuits it does but the current in other cases may lead or lag the voltage.

For a single phase system

Power = Power Factor * V * I

The power factor is the cosine of the angle between V and I and is a maximum (1) in resistive circuits.

well a voltmeter measures AC and DC voltage. resistance is a term used only for DC voltage, A voltmeter uses a term called Impedance for AC, without it, when you measure across two terminals it would create a short circuit and would blow up the meter. it is basically a safety feature to prevent people from creating short circuits when measuring.

Transformer step-up/step-down voltage is turns-ratio, so if a transformer has 20 primary windings and 100 secondary windings (a turns-ratio of 1 to 5) and the secondary voltage is 25, then is the primary voltage is 5.

Soldering iron, solder, flux

A choke is an inductor. The impedance of an inductor is dependent on the frequency of the current flowing through it. The greater the frequency, the higher the impedance.

Therefore an inductor when used as a choke blocks the flow of high frequency current (by presenting a high impedance), while allowing low frequency or direct current to flow through it.

Its function is to block ("choke") high frequencies while passing low frequencies.