Consider the following arrangement of resistors .

This arrangement is immersed in a box containting ice at `0^@)C` . How much ice must be put in the box constant? (Latent heat of ice `L = 80 cal//g`) .

Explanation

`R_(eq)=4+2+1 = 7 Omega I = 10A`
Heat produced in `10 "min"`
`H = i^(2)R_(rq) t = (10)^(2) xx 7 xx (10xx60)=4.2xx10^(5)J`
Let mass of ice melted `m` gram
`H = mL`
`4.2xx10^(5)=mxx80xx4.2`
`m = 1250g = 1.25kg`.