COMEDK2024PhysicsCapacitance
A 5.80 ~F parallel plate air capacitor has a plate separation of 5 mm and is charged to a potential difference of 400 V . The energy density in the region between the plates is
Options
- A283 10⁻² ~J / m ^3
- B2.83 ~J / m ^3
- C2.83 10⁻⁴ ~J / m ^3
- D283 10^6 ~J / m ^3
Correct answer
C. 2.83 10⁻⁴ ~J / m ^3
Step-by-step solution
The energy density in the region between the plates is given by aligned u & = 1 2 ₀ E^2 & = 1 2 ₀ ( V d )^2 ( E= V d ) u & = 1 2 8.85 10⁻¹² ( 400 5 10⁻³ )^2 & =283.2 10⁻¹² 10^6 & =283.2 10⁻⁶ & =2.83 10⁻⁴ ~J / m ^3 aligned