Derive the expression of heat?
Answers
ʜᴇʀᴇ ɪs ʏᴏᴜʀ ᴀɴsᴡᴇʀ-
Consider a resistor of Resistance R. Let the current flowing through the resistor be I and potential difference across its ends be V.
In time t, let Q amount of charge flows through the resistor.
Work done on Moving charge will be,
W =V x Q ---------(1).
According to the definition of electric current,
Q = I x t -----------(2).
Putting equation (2) in (1),
W = V x I x t.
And the work done is dissipated as heat.
Therefore,
Heat produced, H=W=V x I x t => VIt.
H= VIt.
According to Ohm's law V= IR.
Putting this in equation(2), we get,
H= IR x It.
Therefore, Heat= I2(square)Rt.
I square x R x t.
ʙᴇ ʏᴏᴜʀs..........^_^
Joule's law of heating.
All materials offer resistance to the flow of current through them. So some external energy is required to make the current flow. This energy is provided by the battery. Some of this energy gets dissipated as heat energy, so the resistor becomes hot.
Work done in carrying a charge Q through a potential difference V is given as
Also, Q = I t
Using Ohm's law, V = I R
W = I 2 Rt
This work done in carrying the charge th
rough the wire appears as the heat produced. i.e., H = V I t = I 2 Rt.
this energy is dissipated as heat energy