Question

When electric current is passed through a metallic conductor, amount of heat produced in the conductor depends on it
1. material and length only
2. length and thickness only
3. material and thickness only
4. material, length and thickness

Answer 1

Correct Answer - Option 4 : material, length and thickness

CONCEPT:

• Whenever a current is flowing in the resistance then heat is produced in it.
• The phenomenon of producing heat by the electric current is called as the heating effect of electric current.
• The amount of heat produced (H) in joules  = I2 R t

Where I is current, R is resistance and t is the time taken

• The heating effect of an electric current depends on three factors:

1. The resistance R of the conductor i.e., a higher resistance produces more heat.
2. The time t for which current flows i.e., the longer the time the larger the amount of heat produced.
3. The amount of current I i.e.,  the higher the current the larger the amount of heat generated.

EXPLANATION:

Resistance:

• ​It is the ability of the material to oppose the flow of current through the conductor.
• It depends on the following factors:
  • Length.
  • Area.
  • Temperature.
  • Type of material.
• R = p L / A.
  • Where p = resistivity of the material.
  • L = length of the conductor.
  • A = cross-sectional area of the conductor.
• SI Unit = Ohm.
• In the case of a conductor, resistance increases on heating.

Hence, heat produced in the conductor depends on material, length and thickness.