Answer:
2583.9 N/C
Explanation:
Parameters given:
Outer diameter = 14 cm
Outer radius, R = 7cm = 0.07m
Inner diameter = 7 cm
Inner radius, r = 3.5 cm = 0.035m
Charge of washer = 8 nC = 8 * 10^(-9)C
Distance from washer, z = 33 cm = 0.33m
The electric field due to a washer (hollow disk) is given as:
E = k * σ * 2π [ 1 - z/(√(z² + R²)]
Where σ = charge per unit area
σ = q/π(R² - r²)
σ = 8 * 10^(-9) /(π*(0.07 - 0.035)²)
σ = 2.077 * 10^(-6) C/m²
=> E = 9 * 10^9 * 2.077 * 10^(-6) * 2π * [1 - 0.33/(√(0.33² + 0.07²)]
E = 117.467 * 10^3 * (1 - 0.978)
E = 117.467 * 10^3 * 0.022
E = 2583.9 N/C
