A cell of emf `epsilon` and internal resistance `r` drives a current `i` through an extermal resistance `R`
(i) The cell suppllied `epsilon i` power
(ii) Heat is produced in `R` at the rate `epsilon i`
(iii) Heat is produced in `R` at the rate `epsilon I ((R )/(R+r))`
(iv) Heat is produced in the cell at the rate `epsilon i((r ?/(R+r))`

Options

A. (i) , (ii)
B. (ii), (iii)
C. (i),(iii),(iv)
D. all

Answer

C

Explanation

`i=(E)/(R+r)`
Power consumed in `R = i^(2)R = (E^2R)/((R+r)^(2))`
`=(EiR)/(R+r)`
Power consumed in `r = i^(2)r = i*ir`
`=(Eir)/(R+r)`.