In a gun-type bomb, Uranium-235 is the fuel. In an implosion bomb, Plutonium-239 is the fuel. A fusion-boosted atomic bomb uses the implosion design, with the addition of gaseous tritium (Hydrogen-3). Producing the appropriate amounts of fuel for bombs is expensive, time-consuming, and difficult.
What does an inhibitor switch do? An inhibitor switch basically tells your vehicle whether its in motion or in park. It can tell the car to park or to go into first gear etc.
This is a vital component in a vehicle with automatic transmission because it prevents the vehicle startup unless you shift the gear in neutral or in park. When the transmission is in gear, the switch disconnects the starting circuit. This way, you can avoid causing injury to yourself or damage to your car.