Heating effect of electric current class 10 – formulas & Numerical

Last updated on June 24th, 2022 at 09:51 am

In this post, we will discuss the Heating effect of electric current (class 10) and list down the Heating Effect formulas or Equations of electric power and energy. And, then we will solve a bunch of numerical problems as well using these formulas.

Heating effect of current formulas for power and energy

  • The power P dissipated in a component due to the heating effect of current is related to the potential difference (PD) V across the component and the current I in it:
    P = IV
  • The energy E converted in time Δt is E = IVΔt

When either V or I are unknown, then two more equations become available. And these are as follows:

  • Formulas of Power P = IV = I2R = V2/R
  • Formulas of Energy E = IV Δt = I2R Δt = (V2/R) Δt

These equations will allow you to calculate the energy converted into electrical heaters and lamps and so on.

Applications that you may come across include heating calculations, and determining the consumption of energy in domestic and industrial situations.

The heating effect of current numerical – examples solved

1) Calculate the power dissipated in a 250 Ω resistor when the PD across it is 10 V.


P = V2 / R

= 102 / 250

= 0.40 W

2 ) A 9.0 kW electrical heater for a shower is designed for use on a 250 V mains supply. Calculate the current in the heater.


P = IV

=> I = P/V

=> I= 9000/250

=> I= 36 A

3 ) Calculate the resistance of the heating element in a 2.0 kW electric heater that is designed for a 110 V mains supply.


P = V2/R

=> R = V2/P

=> R= 1102/ 2000

=> R= 6.1 A.

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