Question

Mintu wants to increase the heat transfer between a metal iron and another piece of metal he wants to shape. He decides to increase the time the two metals are in contact, use a larger metal iron, and use a new metal material with a higher specific heat.

Where is Mintu's error?

Mintu should have decreased the size of the metal iron.
Mintu should have decreased the time he touches the two metals.
Mintu should have chosen a material with a lower specific heat.
Mintu should have chosen a material the same

Answer 1

Mintu’s error is choosing a material with a higher specific heat.

Reason: Q = mcΔT — a larger specific heat (c) means the workpiece needs more energy to reach the same temperature, so it will heat more slowly for a given heat transfer. Increasing contact time and using a larger iron (more contact area/thermal mass) are correct ways to increase heat transfer.