Q.

A metal cube of side 5 cm is charged with 6 μC. The surface charge density on the cube is             [2024]
 

1 0.125×10-3C m-2  
2 0.25×10-3C m-2  
3 4×10-3C m-2  
4 0.4×10-3C m-2  

Ans.

(4)

Given, charge (q)=6μC=6×10-6C

Length of cube, (l)=5 cm=0.05 m

Total surface area of cube,

(s)=6l2=6×(10.05)2=0.015 m2

Surface charge density, (σ)=Total chargeTotal area

=6×10-60.015=0.4×10-3 cm-2