Advertisements
Advertisements
Question
The heat developed in a system is proportional to the current through it.
Options
It cannot be Thomson heat
It cannot be Peltier heat
It cannot be Joule heat
It can be any of the three heats mentioned above
Advertisements
Solution
It cannot be Joule heat
Joule heat is directly proportional to the square of the current passing through the resistor. Peltier heat is directly proportional to the current passing through the junction.Thomson heat is also directly proportional to the current passing through the section of the wire. Thus, the heat developed can be either Thomson heat or Peltier heat. But it cannot be Joule heat.
APPEARS IN
RELATED QUESTIONS
Define the term 'conductivity' of a metallic wire. Write its SI unit.
Using the concept of free electrons in a conductor, derive the expression for the conductivity of a wire in terms of number density and relaxation time. Hence obtain the relation between current density and the applied electric field E.
Define the term 'electrical conductivity' of a metallic wire. Write its S.I. unit.
The following figure shows a conductor of length l with a circular cross-section. The radius of the cross-section varies linearly from a to b. The resistivity of the material is ρ. Assuming that b – a << l, find the resistance of the conductor.

An electrolysis experiment is stopped and the battery terminals are reversed.
The specification on a heater coil is 250 V, 500 W. Calculate the resistance of the coil. What will be the resistance of a coil of 1000 W to operate at the same voltage?
A heater coil is to be constructed with a nichrome wire (ρ = 1.0 × 10−6 Ωm) that can operate at 500 W when connected to a 250 V supply. (a) What would be the resistance of the coil? (b) If the cross-sectional area of the wire is 0.5 mm2, what length of the wire will be needed? (c) If the radius of each turn is 4.0 mm, how many turns will be there in the coil?
In Figure 3 given below, find the value of resistance x for which points A and B are at the same potential:

figure 3
The ______, a property of materials C, Si, and Ge depends upon the energy gap between their conduction and valence bands.
Consider a current carrying wire (current I) in the shape of a circle.
The electric resistance of a certain wire of iron is R. If its length and radius are both doubled, then ______.
A man covers his body with a blanket of thickness 4 mm. His temperature is 37°C and that of the atmosphere is 27°C. If the coefficient of thermal conductivity of wool is 1.2 × 10-5 MKS units, heat lost by him per hour per square meter area is:
Consider four conducting materials copper, tungsten, mercury and aluminium with resistivity ρC, ρT, ρM and ρA respectively. Then:
