Question

In the figure magnetic field energy stored in the coil is

A. Zero
B. Infinite
C. 25 J
D. None of these

Answer 1

Hint: To answer this question, we first need to understand what energy is.Energy is the quantitative quality that must be delivered to a body or physical system in order to perform work on or heat an object in physics. Energy is a conserved quantity that can be converted in form but not created or destroyed, according to the rule of conservation of energy.

Complete step by step answer:
Ohm's law: The link between electric current and potential difference is described by Ohm's law. The current flowing through most conductors is proportional to the voltage applied to them. Georg Simon Ohm, a German physicist, was the first to experimentally prove Ohm's law.

Inductor: When electric current travels through it, an inductor, also known as a coil, choke, or reactor, stores energy in a magnetic field. An inductor is typically made up of a coil of insulated wire.

Magnetic energy: Magnetism is a force or field that is invisible and is caused by the unique qualities of particular materials. Electrons in most objects spin in a variety of random directions. As a result, they eventually cancel each other out. The molecules in magnets are arranged in such a way that their electrons spin in the same direction.

$Magnetic{\kern 1pt} {\kern 1pt} {\kern 1pt} energy{\kern 1pt} {\kern 1pt} stored = \dfrac{1}{2}L{I^2}$
$L = 2H \\
\Rightarrow I = \dfrac{V}{R}
\Rightarrow I = \dfrac{{10}}{2}
\Rightarrow I = 5A{\kern 1pt} {\kern 1pt} {\kern 1pt} {\kern 1pt} by{\kern 1pt} {\kern 1pt} {\kern 1pt} {\kern 1pt} Ohm's{\kern 1pt} {\kern 1pt} {\kern 1pt} Law \\
\therefore Energy{\kern 1pt} {\kern 1pt} stored{\kern 1pt} {\kern 1pt} = \dfrac{1}{2} \times 2 \times {5^2} = 25J \\ $
So, the final answer is option C.

Note:An inductor is a type of passive electronic component that can store electrical energy as magnetic energy. It works by using a conductor twisted into a coil to generate a magnetic field in the clockwise direction when energy passes into the coil from the left to the right.