E-Bomb

An E-bomb (electromagnetic bomb) is a weapon that uses an intense electromagnetic field to create a brief pulse of energy that affects electronic circuitry without harming humans or buildings.
Functioning/Working:
It works on the principle that changing magnetic fields can induce electric current and a big enough current would fry the semiconductor components in any electrical device, disintegrating it beyond repair.
At low levels, the pulse temporarily disables electronics systems; mid-range levels corrupt computer data. Very high levels completely destroy electronic circuitry, thus disabling any type of machine that uses electricity, including computers, radios, and ignition systems in vehicles.

E-bombs are useful in hi-tech military warfare waged with minimal involvement of foot soldiers. It acts as a good tool for anti-espionage purposes by jamming electronics systems & disabling the intelligence network of the enemy. It also acts as a very effective weapon in anti-terrorist operations and to bring civil war or riots under control because it can create total blackouts on a more local level. 
In modern warfare, an E-bomb could accomplish a number of important combat missions with minimal human casualties and collateral damage. For example, an E-bomb could effectively neutralize:
vehicle control systems
targeting systems, on the ground and on missiles and bombs
communications systems
navigation systems
long and short-range sensor systems

Although not directly lethal, an E-bomb would devastate any target that relies upon electricity: a category encompassing any potential military target and most civilian areas of the world as well. According to a CBS News report, the United States deployed an experimental E-bomb on March 24, 2003 to knock out Iraqi satellite television and disrupt the broadcast of propaganda.
EMP weapons such as E-bombs were especially useful in the invasion of Iraq, because it effectively neutralized the underground bunkers. Most of Iraq's underground bunkers were hard to reach with conventional bombs and missiles. A nuclear blast could have effectively demolished many of these bunkers, but this would have taken a devastating toll on the surrounding civilian areas. However, the  electromagnetic pulse generated by the E-bombs could pass through the ground, knocking out the bunker's lights, ventilation systems, communications -- even electric doors. The bunkers were rendered completely uninhabitable and thus helped the US army to flush out the Iraqi soldiers hiding in those bunkers. The war thus ended in a very short time & with minimum casualties because of these hi-tech weapons.

Advantages & disadvantages:
E-bomb warfare technique implies least number of human casualties & collateral damage, specially in urban areas where the war is being waged.
However, the E-bomb affects only a limited geographical area of only a few hundred yards, thus restricing its usefulness at a large-scale level.

Conclusion:
In the end, the most far-reaching effect of an E-bomb could be psychological. A full-scale EMP or E-bomb attack in a developed country would instantly bring modern life to a screeching halt. There would be plenty of survivors, but they would find themselves in a very different & chaotic world, back in the stone age.