Consider the situation shown in figure. The frame is made of the same material and has a uniform cross-section area everywhere. Calculate the amount of heat flowing per second through a cross section of the bent part if the total heat taken out per second from the end at `100^(@)C` is `130J` .

Options

A. `130 J`
B. `60 J`
C. `70 J`
D. `80 J`

Answer

B

Explanation

(2) Length `AD = 60 cm`
Length of bent part `= 5 + 60 + 5 = 70 cm`
Resistance `prop` length
`R_(1) = 70 R, R_(2) = 60 R`
`i_(1) = (R_(2))/(R_(1) + R_(2)) i = (60 R)/(70 R + 60R) xx 130`
`= 60 J`