Advertisement Remove all ads

Define electric power. An electrical device of resistance R is connected across a source of voltage V and draws a current I. Derive an expression for power in terms of current and resistance. - Science

Answer in Brief

Define electric power. An electrical device of resistance R is connected across a source of voltage V and draws a current I. Derive an expression for power in terms of current and resistance.

Advertisement Remove all ads

Solution

Electric power is defined as the rate of consumption of energy or simply the rate of doing work.
i.e., power, P =`(" work done"("W"))/("Time"("t"))` ..............(i)

The work done by current (I) when it flows in a potential (V) for time (t) can be given by

W = VIt …………………. (ii)

⇒ Power, P `= "VIt"/"t"="VI"`

∴Electric power, P = VI

From Ohm's law, V=VI

Thus, electric power is given by, P = (IR)I = I2R

  Is there an error in this question or solution?
Advertisement Remove all ads

APPEARS IN

Advertisement Remove all ads

Video TutorialsVIEW ALL [1]

Advertisement Remove all ads
Share
Notifications

View all notifications


      Forgot password?
View in app×