How are voltmeter connected to circuit?
Usually a voltmeter is connected across the load whether or not it is AC (Alternating current) or DC (Direct Current). A voltmeter is never connected in series with the load as this may cause serious injury or damage. The meter will absorb the full potential .
What is the difference between a ganged potentiometer an an ordinary potentiometer?
A ganged potentiometer is two or more piggy-backed together that share a common shaft. Turn the shaft and you turn all the pots at the same time. Commonly used to adjust the volume or tone for both channels of a stereo amplifier at the same time. An ordinary pot has just one to a shaft!
Importance of color coding in carbon resistor?
color coding of resistor:black,brown,red,orange,yellow,green,blue,voilet,grey,white
these colors are ranked as:0,1,2,3,4,5,6,7,8,9
tolerance:silver,gold,no color
ratings:5%,10%,20%
Why does the chord of an electric heater not glow while the heating element does?
The element is made of special high resistance wire so the power is dissipated in the element rather than the low resistance cord.
Power(watts) = Resistance (ohms) X {Current(amperes)}squared
to determine the total resistance, you add them vectorilly,first find the inductive reactance of the inductor by the following formula: 2 pi F L (2x3.14 x frequency in herts x inductance in henrys) next, consider the inductive reactance and the resistance as the two sides of a right triangle and the hippotanus would be the total impedance.(this combined ''resistance'' is called impedance.) to determine the total resistance, you add them vectorilly,first find the inductive reactance of the inductor by the following formula: 2 pi F L (2x3.14 x frequency in herts x inductance in henrys) next, consider the inductive reactance and the resistance as the two sides of a right triangle and the hippotanus would be the total impedance.(this combined ''resistance'' is called impedance.)
What is super heterodyne receiver?
A superheterodyne receiver is a Radio Frequency receiver method that multiplies the received signal frequency with a local oscillator frequency to get frequencies that are the sum and difference of the 2 frequencies. For example, if the received signal is 5MHz and the local oscillator frequency is 4MHz, they are multiplied together. 1MHz and 9MHz frequencies would be gotten. Usually the 1MHz is the Intermediate Frequency (IF). It will be admitted (through a band pass filter) later passed through the required electronic circuits for proper processing. There is also the method of the Variable Tuned Filter.
Will the lightbulb be brighter in series circuit or brighter in a parallel circuit?
This question is the wrong way round. Assuming you the light bulbs are identical, they are brighter when connected to the power source in parallel than in series. This is because each bulb uses the entire potential difference of the power source, whereas in series, the bulbs act as potential dividers, reducing the voltage across the others and therefore the current passing through all of them.
What happen to current when paralle resistor added?
For the individual resistor, the current is constant, regardless of any other resister that's attached to it in parallel. The current that results from all the resistors combined decreases as the resistance of one or more of the resistors increases.
What are the different generations of microprocessors?
NO DIFFERENCE they all use the basic three units. I/O, ARITHMETIC and PROCESSOR. The difference is enhancement of the products. Speed buss with more bits per byte I/O speed and a co processor to alleviate overhead of I/O management.
How does a bulb in a circuit light up?
A light bulb (called a lamp by the industry) will emit light when a voltage is applied to it. The applied voltage causes current flow through the lamp, and the lamp responds by emitting light. (There are many different lamps and they work differently, and we're generalizing here.)
The lamp doesn't care whether the voltage that drive current through it comes from. It responds to the voltage (and current flow) according to its rating. If a given voltage is nominal for a lamp under inspection and we apply that, that lamp can be powered up by a generator, a battery, solar cells, or a number of other sources. Apply the appropriate voltage, and the lamp responds.
What happen to the parallel circuit if one resistance is removed?
assume the following configuration: battery connected to 2 parallel resistors with an ammeter in series with the battery... observe the current measurement ... remove one of the resistors .... observe the current again, it will have decreased: if the resistors were of equal value, the current will decrease to half of its original value when one of the resistors is removed. Mathematics:
V=IR (V- voltage, I - current, R - resistance
in a parallel circuit, R=(R1*R2)/(R1+R2) where R1 and R2 are the values of resistance of the resistors. Before removal- Ib=V*(R1+R2)/(R1*R2)
After removal (assume R2 is removed)- Ia=V/R1
so Ia/Ib=(R1*R2)/(R1*(R1+R2))
or Ia=Ib*(R2/(R1+R2)
if R1=R2 then Ia=Ib*R2/(2*R2) or Ia=Ib/2 so the current after is 1/2 of that before.
How do you solder an integrated circuit without causing any damage?
Wear eye protection, as solder has been known to spit (bubble). Wear gloves (solder is very HOT). Keep your workplace dry when using an electric soldering gun. Keep flammable liquids and materials away from the work area. Keep your work area clean and clutter free. Never leave a hot iron or gun unattended.
What is the concept of a hole in semiconductors?
A semiconductor material forms a crystal structure where all the valence electrons "participate" in forming the lattice. There are neither "extra" nor "missing" electrons in the structure. If we dope the semiconductor with a "P-type" material, this sets the stage for the creation of a "hole" in that matrix. The P-type material will have one less valence electron than our semiconductor material. And when that P-type atom becomes part of the crystal matrix, it lacks that one electron to make the matrix "complete" or "uniform" as regards the electrons. That creates the hole in the matrix. When that P-type material is formed up against N-type material (which has an "extra" electron in its matrix), that extra electron will leave the N-type material and migrate to the P-type material to fill that hole. This sets up a condition where charges have shifted, and it creates a difference of potential (voltage) across the junction (owing to the shift of the electrons).
Why is air a better insulator than solids?
.air you can breath and if there was no air there would be no things that live out of sea
What is the function of the wire in an electric circuit?
Wires are necessary to make a complete electrical circuit.
For example they are needed to bring the electricity to the load (like a bulb) from one side of the source (like a battery "+" terminal) and then take it back to the other side of the source (the battery's "-" terminal).
Another take
A wire allows the electricity (called Current) a path to travel through it, based on the difference in potential (aka Voltage) between the components (for example, Resistors).
Key note: the wires must be connected to make the path a complete LOOP. i.e. if there is no connection back to where you started from, there is no flow.
To describe it more completely:
Current flows through components as well. So, say if the resistor is a light bulb and the filament blows, then the loop path is not complete anymore.
After you get this idea search for the term "Ohm's law" to get a handle on electric circuits. (Kirchoff's voltage law and Kirchoff's current law are the other big ideas)
Oh, and in case you didn't know: the battery is the thing making "the difference in potential" I talked about. Additionally: Resistors aren't the only components: the other 2 are called Capacitors and Inductors. In circuit analysis they function as a slightly more complex form of Resistance that's called Impedance.
What are applications of cathode ray oscilloscope?
If an analog oscilloscope is used the actual visual performance of a circuit can be displayed. The limitation is hi frequency. A digital scope will outperform an analog scope in digital however the display is fabricated by hi freq chopping. Another scope is a memory scope whereby a sample is taken for further study of a signal it will not change but slowly decay. ALL OS THESE ARE APPLICATIONS NONE IS BETTER THEN THE OTHER
What is meant by the turns ratio of a transformer?
Hi,
The turns ratio depends on the amount of windings in a transformer that are needed to provide a secondary voltage/current that's different from the primary AC source. The ratio is derived from how many windings on the primary side as compared to the secondary side.
Hope this helps,
Cubby
How many mAh is a D size battery?
That would depend on the actual battery's specifications. I've seen some D cells rated as low as ~2000 mAh. However a full true D cell should have a rating between 10,000 mAh and 15,000 mAh.
Why 3 db is used in bandwidth?
The 3 dB point belongs to the cutoff frequency or the corner frequency. There the 100 % voltage is then down to 70,7 % and the power is down to 50% at the same time.
Rms value of sum of two sine waves?
question is not clear. RMS is .707 of peak. If you're asking about sums of currents or voltages represented by sine waves and they don't have the same frequency then the sum's RMS value is the square root of the sum of the squared amplitudes of the two waves. The squared amplitudes are proportional to the power in each current or voltage and the result represents the sum of the powers.
If the two sine waves have the same frequency then the sum's RMS value is the sum of the two RMS values. The physical circuit has to add power to the signal. (if the amplitudes are equal the resultant will have 4 times the power)
What is zener break down voltage?
The point in the forward operating region of the characteristic curve where conduction starts to increase rapidly is called Knee voltage of a PN Junction Diode.
The breakdown voltage of a diode is the minimum reverse voltage to make the diode conduct in reverse.(or) Breakdown voltage is a parameter of a diode that defines the largest reverse voltage that can be applied without causing an exponential increase in the current in the diode.
-- Dinakar
What happens to current in a circuit if the voltage is halved and the resistance stays the same?
the current doubles..
explanation:V=IR hence I=V/R which means that when the supply voltage is constant ,current is inversely proportional to resistance.thus the current doubles.
practically speaking when the resistance of the load(fan ,bulb,refrigerator,....) is less ,it draws more current from the source so as to balance the voltage across it.i.e; to maintain the voltage across it as constant.
This answer is absolutely correct if you assume that the current comes from a pure voltage source ( voltage source with zero internal resistance). At the other extreme you could have a current source (such as a very large voltage source in series with a very large resistor), and then the current is practically independent of changes if the external resistance is changed (because the change represents a relatively minute change in the overall resistance). With appropriate circuitry it is possible to devise a situation where the current is practically independent of the changing resistance.
A light using two (or more) electrodes in a glass tube filled with a mixture of inert gases. The most common (and the source of the name) is neon gas, which produces a red light when ionized by current flow between the electrodes. Helium, argon, and xenon are used in the mixture to produce other colors. Sometimes neon lights have a tiny amount of tritium gas added because the radioactivity pre-ionizes a little of the inert gas making it easier to start current flow to ionize the rest of the gas and produce light.
One type of neon light used in older electronic equipment that displayed numbers called a Nixie tube typically had 12 electrodes in a cylindrical glass tube: one electrode was common, ten of the electrodes were shaped like the digits 0 to 9, and the last electrode was a decimal point.