A piece of pencil lead is connected in series with an ammeter and a power supply. The power supply is turned on. After a few minutes, although the potential difference across the pencil lead does not change, the current in the circuit increases significantly. Explain why the current increases.

More electrons become free due to the potential which are charge carriers. More the charge carriers, more the current.

Current causes a heating effect. Resistance of lead decreases/ n increases [I=nAve]. Current increase

Explanation:

coil wire, increase current, put iron inside the coil

another example of kinetic energy would be,

kinetic energy   >     moving energy

answer   >   letter choice (c),   a hammer falling off a table.

hope that !                                         : )