Both Physical and chemical changes.
An electromagnet is a device in which, by electric current, the magnetic field is produced. Increase the number of coils and increase the strength of the current, thus, increasing the strength of an electromagnet.
The correct option is B.
<h3>What is an electromagnet?</h3>
An electromagnet is a device that consists of a magnetic core encircled by a coil, through which an electric current is carried to magnetize the core.
Wherever controllable magnets are required, such as in devices where the magnetic flux must be adjusted, reversed, or switched on and off, an electromagnet is utilized.
Thus, the correct option is B, increasing the number of coils and increasing the strength of the current.
Learn more about electromagnet, here:
brainly.com/question/13803241
Does mass<span> alone provide no information about the amount or size of a measured quantity? No, we need combine </span>mass<span> and </span>volume<span> into "one equation" to </span>determine<span> "</span>density<span>" provides more ... </span>g/mL<span>. An </span>object has<span> a mass of </span>75 grams<span> and a volume of </span>25 cc<span>. ... A </span>certain object weighs 1.25 kg<span> and </span>has<span> a </span>density of<span> </span>5.00 g/<span>mL</span>
D will because water just turns from liquid to a gas by adding heat. That is a physical change. The other equations are chemical changes.