Q.

The quantities of heat required to raise the temperature of two solid copper spheres of radii r1 and r2(r1=1.5r2) through 1 K are in the ratio        [2020]
 

1 278  
2 94  
3 32  
4 53  

Ans.

(1)

Heat required, ΔQ=msΔT

ΔQ=(V×ρ)×sΔT

=43πr3ρ·s ΔT

ΔQ1ΔQ2=r13r23=(r1r2)3=(1.5)3=278