Joan makes the device shown in her science class. what would happen to the magnetic field if she connects the battery in the opposite direction? a) the field would stop. b) the field would get stronger. c) the field would reverse its poles. d) the field would get weaker.

the answer is C) The field would reverse its poles.

C) The field would reverse its poles.

Explanation:

The given diagram shows an electromagnet. A iron nail is placed between coil through which current is passes as it is connected to the battery.

When the terminals are reversed, the current still flows but in the opposite direction. Magnetic field is still generated but with the reversed poles.  

Magnetic field produced:

B = μ n I

The direction of the magnetic field reverses with the direction of the current.

ok

explanation:

the order for strong to weak forces such as

strong nuclear force → electromegnetic force → weak nuclear force → gravitational force

the fundamental forces are those forces that act between to objects or element to make interactions. there are four types of fundamental forces such as strong and weak nuclear forces (due to protons and electrons), electromagnetic force (due to the motion of electrons) and gravitational force (due to orbital movement of the planet). if these forces are arranged on the basis of their maximum strength then the order is

strong nuclear force → electromegnetic force → weak nuclear force → gravitational force