NEET2026PhysicsChapterActual
A thin rectangular metallic plate of dimensions 15 cm 20 cm is given a total charge of 12 C . Assuming uniform charge distribution, the magnitude of surface charge density on the plate is
Options
- A4 10⁻⁴ C m ⁻²
- B2 10⁻⁴ C m ⁻²
- C4 10⁻⁵ C m ⁻²
- D2 10⁻⁵ C m ⁻²
Correct answer
B. 2 10⁻⁴ C m ⁻²
Step-by-step solution
Total charge given to the metallic plate, Q = 12 C = 12 10⁻⁶ C . Area of one surface of the plate, A = 15 cm 20 cm = 300 cm ^2 = 3 10⁻² m ^2 . Since it is a thin metallic plate, the charge distributes uniformly over both of its outer surfaces. Charge on each surface, q = Q 2 = 6 10⁻⁶ C . Surface charge density, = q A = 6 10⁻⁶ 3 10⁻² = 2 10⁻⁴ C m ⁻² . Answer: 2 10⁻⁴ C m ⁻²