IP Consider a parallel-plate capacitor constructed from two circular metal plates of radius R. The plates are separated by a distance of 1.4 mm .
(a) What radius must the plates have if the capacitance of this capacitor is to be 1.8

Required radius of the plates = 9.52 m

Explanation:

C = (Aε₀)/d

C = 1.8 × 10⁻⁶ F

A = ?

ε₀ = 8.8542 × 10⁻¹² F/m

d = 1.4 mm = 1.4 × 10⁻³ m

A = Cd/ε₀ = (1.8 × 10⁻⁶)(1.4 × 10⁻³)/(8.8542 × 10⁻¹²) = 281.61 m²

Area of the plate = πr² = 281.61

r² = 281.61/π = 90.59

r = √(90.59) = 9.52 m

good for her? ? where is the question?

answer: 802.3 kilo joules of energy represents 191.75 kilo calorie of energy.

explanation:

energy released during combustion of one mole methane = 802.3 kilo joules

if 1 kilo joule = 0.239006   kilo calorie

then ,802.3 kilo joule will be = 802.30.239006 kilo calorie

802.3 kilo joule = 191.75 kilo calorie

hence, the energy in kilo calorie is 191.75 kilo calorie.