The emp effect last for only milliseconds, much much less than one second. EMP bombs are NOT highly explosive. They do very little damage from the explosive force. The damage is ALL done from the EMP. talking about an EMP of "100 kilo-tons" is senseless.
An EMP bomb depends on a simple law of physics:
"If a magnetic field is moved around a coil of wire, an electrical current will be generated."
-- AND --
"The bigger the magnetic field, the large the electric current."
A "coil" does not have to be all coiled up! A "coil" of wire COULD be a simple extension cord, or the high-tension lines on those big metal supports.
The idea of an EMP is to generate a HUGE magnetic field. This field will generate a LARGE voltage in ANY electronic device -- thus "frying" it. Such an EMP would fry every chip in a computer or cell phone or laptop. It could melt all the wires in an automobile or airplane.
ANYTHING with wires in it will be damaged -- light bulbs, televisions ets, toasters, automobiles, generators, hair dryers. computers, cell phones, and so on. ANY alectronic device will be damage, and probably made non-repairable. Small devices like cell phones could actually melt, or the batteries could catch fire or explode..
The OLDER a device is (like a car) the more likely it is to SURVIVE. An OLD model car, like from the 1970s, doesn't have all those new fangled computers and such in it. It might be repaired with some new spark plug wires and a new alternator. Something like a Prius would be totally lost. Some electric cars use motors in the wheels. Those motors could actually catch the tires on fire!
A bicycle, having NO electric parts, would not be damaged! Thus, our first form of transportation to get "back oon live" will be walking, horse and buggy, and bicycles.