Question

159. Two plates of same area are placed in contact.
Their thickness as well as thermal conductivities
are in the ratio 2:3. The outer surface of one plate
is maintained at 10 °C and that of other at ( °C.
The temperature of the common surface is
a)0 °C
b) 2.5 °C
c)5 °C
d) 6.5 °C
100 The brortance and reflectance of obiect is​

Answer 1

it may be the answer is 2.5