Answer:
Step-by-step explanation:
The drum is in the form of charged cylinder .
Electric field near a charged cylinder = λ /2πε₀r
λ is linear charge density ,
3 x 10⁵ = λ /(2 x 3.14 x 8.85 x 10⁻¹² x 0.06)
λ = 2 x 3.14 x 8.85 x 10⁻¹² x 0.06 x 3 x 10⁵
= 10 x 10⁻⁷ C/m
Total charge on the cylinder
= .42 x 10 x 10⁻⁷
= 4.2 x 10⁻⁷ C
b )
New diameter = 6.2 cm
radius = .031 m , for same electric field
3 x 10⁵ = λ /(2 x 3.14 x .031 x 8.85 x 10⁻¹² )
λ = 2 x 3.14 x .031 x 8.85 x 10⁻¹² x 3 x 10⁵
= 5.168 x 10⁻⁷
Charge on the cylinder
= 5.168 x 10⁻⁷ x .22
= 1.25 x 10⁻⁷ C
Charge on new drum
= 1.25 x 10⁻⁷ C
