Question

100 POINTS I NEED HELP ASSAP

Which of the following factors would decrease the magnetic field strength of an electromagnet? (1 point)
O increasing the number of turns in the coil of wire
O increasing the current or using a higher-voltage power source
O increasing the distances between the turns of the coil
O using an iron core or nail

Answer 1

increasing the distances between the turns on the coil

Step-by-step explanation:

`B = (\mu N I)/(L)` where B i the magnetic field strength,
`\mu` is the permeability of the core which is very large for iron compared with that of air, N is the number of turns, I is the current and L is the length.

Keeping all the other parameters constant,

if N is increased then B is increased

if I is increased then B is increased

if the distance between coils is increased then L has increased and B had decreased

if iron is added to the core
`\mu` has increased so B has increased