Determine the energy (in J) stored by a 0.4 H inductance, If the current flowing through it is 2A

• A. 0.4
• B. 1.6
• C. 1.4
• D. 0.8

Answer: (D)

Energy in a Magnetic Field of inductance
The magnetic flux of the current in inductance is the electric energy supplied by the voltage source producing the current. The energy is stored in the magnetic field since it can do the work of producing the induced voltage when the flux moves. The amount of electric energy stored is
Energy = ½LI2 joule
Given
Inductance H = 0.4Current I = 2A
E = ½ × 0.4 × 22
E = 0.8 Joule