3. If the potential difference is 120 volts and the resistance is 60 ohms, what is the current?

2 amperes

Explanation:

According to Ohms law

v = ir

v = voltage

I = current

r = resistance

From the question

v = 120volts

r = 60 ohms

I = ?

Using ohms law ,

v = ir

120 = I x 60

Divide both sides by 60

120/60 = I x 60/60

2 = I

I = 2 amperes

what experimental evidence led scientists to change from the previous model to this one?

a few of the positive particles aimed at a gold foil seemed to bounce back.

the colors of light emitted from heated atoms had very specific energies.

experiments with water vapor showed that elements combine in specific proportions.

cathode rays were bent in the same way whenever a magnet was brought near them.

the answer is the first electromagnet (a). this is because it has more coils around the ferromagnetic material. increasing the number of coils increases the surface area in which the metal interacts with the current in the coil. this enables more atoms in the metal to become aligned hence becoming more magnetized.