The current in a wire increases from 5 A to 10 A, what happens to its magnetic field?
The field is twice as strong
the distance of a charged particle from a wire changes from 10 cm to 20 cm, what happens to its magnetic field?
the charge of a particle changes from 2 uC to -2C, what happens to the force exerted on that particle?

Which of the following correctly describes what happens when an atomic bomb explodes? small pieces of fissionable material are joined and form a body with a mass greater than the critical mass, the relative number of neutrons escaping decreases, and a chain reaction and explosion result. large pieces of fissionable matter are brought together quickly and form a body with a mass smaller than the critical mass, the relative number of escaping neutrons increases, and a chain reaction and explosion result.