Set in the near future, thousands of killer robots resemble those featured in the terminator film, I'm referring to the 800 series model are now marching in as we speaks. I am a sole survivor on a tall mountain and I have put up a powerful emp with effective range of 10km, is it sufficient to deter the killer robots? I was hoping the Electromagnetic Pulse(EMP) would fry their circuitry when they got too close and as a preventive measure I covered a large area with heavy duty electromagnet which can output a magnetic field of around 50 tesla...
There are several problems with this, not the least of which is that you've just created an EMP that is comparable to a lightning generator in terms of range, but your lightning is not a ranged weapon; it strikes specific points where resistance is lowest.
This is good news for your power consumption, because if you can hit one of the robots with it, then you've put all your energy into a single robot, maximising your chances of taking it out. But, there's several pieces of bad news attached to this.
1) You are closer to your weapon than the robots are.
The lightning generator is looking for the path of least resistance to earth it's energy, and the closer you are, the more likely it is that you are that path of least resistance. You need to be in a bunker while all this is happening, and your bunker can't have trees, lightning rods (obviously) or any other weak point that could attract the lightning instead of the robots.
2) EMPs are easier to survive than one thinks.
Looking back through history, we find that even Apollo 12 got struck by lightning, and not only survived, but went on to complete its mission to the moon and back. In fairness, NASA had considered everything in their design of the Apollo missions, including lightning strike. But also in fairness, no-one's going to invest in robots that have such an obvious flaw to an obvious weapon without putting in some form of hardening.
3) The return of shield tactics.
Your killer robots are just as likely to carry big metal shields with them, like the knights and warriors of old. Why? Well, if they do, not only can they protect themselves from close quarters but low power weapons, but they can bring back the Turtle, or testudo formation. It may sound silly, but if you do it right with metal shields designed the right way, you have a great modular faraday cage that your robot soldiers carry into the field with them. They could just wait for you to run out of power.
EMPs sound like great weapons, but when you get right down to it even most commercial equipment of any value, like passenger aircraft, are hardened in some manner against EMP strikes like lightning. There are some other forms of EMP that they're NOT protected for, like nuclear pulses, but they're going to do more damage to your own people than they are to the robots, and aircraft like the B1 and B2 are allegedly EMP hardened against nuclear pulses now, meaning that in theory at least, the same could be done to your killer robots. Also, EMPs as field weapons can't generate a 10Km effective range without doing even more damage to those close in to the blast, and in this case that means you.
Another way of putting this is that EMPs are NOT siege defense weapons. They're designed for tactical deployment in an area that only contains enemy equipment because of the indiscriminate nature of the weapon, and in a war where electronically controlled equipment is the primary weapon, EMP hardening will be done on all combat equipment before the war even starts. Add to that the fact that these weapons are not going to cause permanent damage in most cases, meaning you have to dismantle the equipment while it's down, and there simply has to be better ways of disabling your robot horde.
The killer robots can deploy a faraday cage around your Electro Magnetic Pulse (EMP) generator and defeat it. This would be if they are unable to launch an all-out offensive against the generator in the first place to remove it's ability to stop them.
Alternatively, the robots could wear their own faraday cage suits which would dramatically reduce the effect of an EMP on their operation against you.
You might need a multi-attack approach to focus on multiple weaknesses to defeat your enemy. Tiny EMP generators to take out individual robots, jam any frequencies they use for communications, use devices to render their motors inoperable.
Tough. Because the EMP decays with the square of the radius (distance from source).
You should've prepared yourself with a bunch of explosive EMP grenades and invest into a grenade launcher or mortar. It would have bought you a few days more under the Sun anyway.
I covered a large area with heavy duty electromagnet which can output a magnetic field of around 50 tesla...
Meh, with a bit of care, those explosively pumped flux compression grenades would have got you from 3.8T to 1000T (PDF warning).
Modern military equipment is hardened against EMP, and that shiny metal shell around a Terminator probably functions as a Faraday cage and protects them. However, all protection has its limits, and a powerful enough EMP generator will keep them at a certain distance. (arbitrary as we are talking SF technology)
However, the EMP will equally stop you from using any electronic-based technology. And it will not stop the Terminators from lobbing artillery rounds and other long-range weapons at you. If they're clever they'll send a pack of attack dogs :)