Question

why is the diurnal range of temperature during summer greater at bikaner(rajasthan) than at panjim(goa)

Answer 1

It's because in rajasthan the day them is extreme and the night temp is also extreme and in goal the same doesn't occurs so the diurnal temp range in rajasthan (bikaner) is high than Goa(panjim)

Answer 2

Because in Rajasthan in summers the sand got very fast hot in day and in night goes very cold