Coiling wire around an iron core and applying an electric current through the wire creates a temporary magnet called an electromagnet. what would increase the strength of an electromagnet? a) use a smaller nail. b) use a battery with less voltage. c) use a battery with more voltage. d) use fewer coils of wire around the nail.

C) Use a battery with more voltage.

Explanation:

The equation for the magnetic field around a coil is given by,

B = μ₀NI

where,

B = Magnetic flux density

μ₀ = permeability

N = number of turns per meter

I = Current in the wire

So when using a higher voltage battery, more current passes through the battery as resistance of the wire remains the same.

electrical potential energy =0.072 j

explanation:

electrical potential energy is given by

u= q δv

q= charge=6 c

δv= potential difference and is given by

δv= e d

e= electric field

d= distance=5 mm=0.005 m

δv=2.4 (0.005)=0.012 v

now electric potential energy= u= q δv

u=6 (0.012)

u=0.072 j