Electronics Engineering

Conductance is the reciprocal of resistance, and is measured in siemens (S).

So a 5.1 ohm resistor has 1/5.1 conductance,

which is approximately 0.196 078 431 372 549 019 607 843 137 254 9 S.

It must (i) increase, or (ii) decrease, or (iii) stay the same.

If (iii), there's no point in having it at all,

so consider what happens to stage gain at the lowest frequencies, as the capacitor has less and less effect on the circuit.

DC input refers to the direct current electrical input provided to a device or circuit. Unlike alternating current (AC), which periodically reverses direction, DC maintains a constant voltage and direction, making it suitable for many electronic devices, batteries, and power supplies. DC input is commonly used in applications like batteries, solar panels, and electronic circuits where stable voltage is essential.

The color bands show the nominal resistance. The actual resistance is within some percentage (tolerance) of the nominal resistance, so the measured resistance is close to the nominal but not exactly the same. Also resistance varies with factors like temperature and age of the device.

The potential barrier in silicon is higher due to its relatively larger energy bandgap compared to other materials, such as germanium. This bandgap, approximately 1.1 eV for silicon, requires more energy to excite electrons from the valence band to the conduction band, thus creating a larger potential barrier for charge carriers. Additionally, silicon's crystal structure and doping levels influence the height of the potential barrier, affecting charge transport properties in semiconductor devices.

Using a higher voltage reduces power losses during transmission.

• SDH and PDH are two digital hierarchies in which different line speeds (e.g. E1, T1, STM1) are categorized.
• PDH (plesiosynchronous digital hierarchy) was replaced by SDH (synchronous digital hierarchy) due to its drawback in synchronisation where plesio refers to nearlysynchronous.
• E1, T1 and J1 are generally categorized under PDH. STM1, OC3, STM4, OC12 etc. are categorized under SDH.
• E1 is used worldwide nowadays in 2G technologies except North America and Japan (who are using T1 and J1 respectively). It is the line speed of 2Mbps. But how this speed comes along? The derivation is as follows.
• The audio signals were sampled and converted to digital signal at 64kbps, since 1960s for digital transmission of voice calls. When 32 channels (30 assigned for voice channels and 2 channels for framing and signaling), with each having speed of 64kbps are put together (or we call multiplexing), a line speed of E1, i.e. 2Mbps is produced by having 32 x 64kbps = 2.048Mbps.
• T1 line, which transmits at 1.544 Mbps can be interconnected with E1 for international use.
• Having 3 different speeds (E1, T1 and J1), PDH was later replaced by SDH in order to standardize the speed, making only 1 standard speed worldwide, which is STM1 having the speed of 155.52Mbps.

E=sin(Theta);

You need to normalize the equation for the electric field of the half-wavelegnth dipole. recall E=sqrt(ExE*) where E* is the conjugate of the E field.

This is why you only get an eight shaped figure (or infinity symbol) when you plot it. you will get this figure if the dipole is placed in the axis of interest. e.g. if it is in the placed in the x axis, you will get an eighth in the x-y,x-z, but you will get a donut shape in the y-z (no angle to measure)

hope this helps a bit.

operating point of dc load line refers to point where there is no signal either no amplification use to take place as base current is zero(in case of common emitter configuration) and it is represented by Q.......

passive attacks : footprinting, trashing

active attacks : sniffing, social engineering

It's what happens when a battery is about to expire.

there are no good or bad conductor there are conductor ,semiconductor and isolator.

what is communication system explain with block diagram.

The term Microwave is a description of a high frequency radio wave in the range of 1 Gigahertz (One million cycles per second) to 40 gigahertz (40 million cycles per second). Radio waves at this frequency have the tenancy to reflect & refract making them useful for a wide number of applications.

Also since the radio wavelength is related to the frequency (frequency in Hertz divided by the speed of light in metres per second equals wavelength) the aerial size for this band is very small allowing for the use of exotic aerial systems such as dishes.

Dish aerials (antenna) are extremely efficient reflectors for microwave transmitters producing point to point links which can operate over many miles. Unlike High low and medium frequency Transmitters, microwave frequencies are not affected by the ionisation of the gas layers in the atmosphere. Therefore they tend to pass straight through the atmosphere rather than being reflected or refracted back to Earth. This makes them very useful for space communications and radio astronomy.

Microwaves do have some problems though. It is relatively expensive to generate high output at microwave frequencies. Also the nature of microwaves is that they do not pass through solid or grounded objects. This means that rain clouds can block the signal. Also at high power, microwaves excite water molecules, causing them to heat up (this is the principle of the microwave oven). Therefore inappropriate use can be hazardous to health.

Microwave are used to locate ships and planes, track weather systems, and determine the speeds of moving objects. They are the principal carriers of television, telephone, and data transmissions between stations on Earth and between the Earth and satellites.

Reverse voltage is voltage is applied in reverse. Instead of the positive voltage going into the anode lead of a component, it goes into the cathode lead of the component.

There are an infinite number of possible combinations to create an electric circuit.

It will simply not be possible to answer it correctly due to lack of information from absolutely all the developers around the world.

Even by limiting an answer to smaller circuits, this question is a challenge.

Even the simple light bulb is an electric circuit. How many different bulbs don't we find around the world these days? We have fluorescent bulbs, low voltage bulbs, high voltage bulbs, metal halide bulbs, halogen bulbs, this most likely in the thousands of different varieties from different manufacturers.

I would simply count on many many millions of different electric circuits. A lot of which would be similar work-wise, but still different maybe only by color.

This is only an educated guess that is in the area of many million's+ and then some.

By combining parts in order to make other circuits, the number grows unfathomable large pretty soon. The question only asks about what have been mad. Not what can be made. By this, we know the number can not be infinite, but we know the number to be large.

Each house around the world is an individual electric circuit. Each being different, however some more than others. We are 5 Billion people on this planet of ours. If there are 5 people in each house, then there must be 1 Billion houses with each a slightly different electrical circuit.

This may because specs of dust can cause activation of the detector as it has the same effect as smoke. Spiders also can crawl into the sensors which does the same thing- same way with deodrant, paintfumes etc. It also may be because the smoke detector is just faulty.

In FM the carrier is still present and the power is still there, at a constant amplitude at the transmitter. It's only the frequency of the carrier that alters, in time with the audio applied to it. The louder the sound the further the frequency shifts.

High frequency is used because of the the size of antennas used to transmit and receive the communications signal. The higher the frequency the smaller the antenna.

Well, yes they do. Any amplification adds noise to the signal. Some of this can be removed but the effects are cumulative. Imagine making a copy of a piece of music by an analog technique. Then making a copy from that copy, etc. You get more and more noise added to the system, even when the amplification is one. In digital systems, the music (or whatever) is made of bits that are either there or not. Cleaning up the bits is very easy. Perfect copies are typical.

You would use a supply bypass capacitor in a common collector amplifier...

It's necessary, to give the positive supply rail a direct AC connection to ground. Without it, I don't think the amplifier would work properly. However, if you're using a power supply and not a battery, then chances are that it HAS a big capacitor inside it, eliminating the need for any external capacitor.

Here are a couple. Assuming everything is "normal" here, if you drop a bagel in the toaster and turn it on by pushing the lever down, the AC current the toaster uses (draws) will stabilize after a few seconds and stay constant. If you turn on your car's headlights, each lamp will draw a constant current from the DC source after a few seconds of "warm up" time. Those are examples of constant electric current.

Thanks for your contribution and thoughts but you CAN use a 4.2 volt charger for a 3 volt battery.

Jyot


No. You should not use a 4.2V charger for a 3V battery. The charger is specifically designed for the battery. Attempting to use a non rated configuration, unless the charger states clearly on its label that it can handle the 4.2V battery, could result in overcharge, overheat, even fire.

Even attempting to place a resistor or zener diode in series with the battery is not a good idea, because some chargers use the voltage/time curve to sense when the battery is fully charged, and this will bias the results.