Question

A solar heating system has a 25.0% conversion efficiency; the solar radiation incident on the panels is 1 000 W/m2.

Answer 1

Answer:

Rise in temperature will be $28.7^{\circ}C$

So option (c) will be the correct answer

Explanation:

We have given solar radiation on the panels $=1000w/m^2$

25 % of the conversion efficiency = 25 % 1000 = 250

Area is given $A=4m^2$

So radiated power $P=250\times 4=1000watt$

Time is given t = 1 hour = 3600 sec

So energy $E=power\times time=1000\times 3600=3.6\times 10^6J-sec$

Mass of water m = 30 kg

And $c_w=4.186$

So rise in temperature $\Delta T=\frac{Energy}{m\times c_w}=\frac{3.6\times 10^6}{30\times 4.186}=28.7^{\circ}C$

So option (c) will be the correct option