NEET Physics: Thermoelectricity questions with solutions

Q1. The heat developed in a system is proportional to the current through it. Then

1. it cannot be Thomson heat.
2. it cannot be Peltier heat
3. it cannot be Joule heat.
4. it can be any of the three heats mentioned above

Answer: it cannot be Joule heat.

Joule heating is given by I²R, so it varies as the square of current, not directly proportional to current. Thomson and Peltier heats are proportional to current, so the statement rules out Joule heat.