Blog Post

Grade 1

Grade 2

Grade 3

Grade 4

Grade 5

Grade 6

Grade 7

Grade 8

Grade 9

Grade 10

Grade 11

Grade 12


<figure class="wp-block-image size-full"><img loading="lazy" decoding="async" width="940" height="216" src="https://www.turito.com/learn-internal/wp-content/uploads/2022/08/image-3228.png" alt="" class="wp-image-9274" srcset="https://www.turito.com/learn-internal/wp-content/uploads/2022/08/image-3228.png 940w, https://www.turito.com/learn-internal/wp-content/uploads/2022/08/image-3228-300x69.png 300w, https://www.turito.com/learn-internal/wp-content/uploads/2022/08/image-3228-768x176.png 768w" sizes="auto, (max-width: 940px) 100vw, 940px" /></figure>



<h2 class="wp-block-heading"><strong>Introduction</strong><strong>:</strong>&nbsp;</h2>



<p>The electric potential produced by changing <a href="https://www.turito.com/blog/physics/magnetic-declination">magnetic </a>flux is called induced electric potential. The induced electric potential is also called electromotive force (Emf). The electromotive force (Emf) is the electric potential that is generated when there is a transfer of energy from one form to another. Like producing electrical energy by changing magnetic field. </p>



<p>Whenever there is a change in the magnetic flux linked with a closed circuit, an emf produces a current known as induced current. However, it lasts only as long as the magnetic flux is changing.&nbsp;</p>



<h3 class="wp-block-heading"><strong>Explanation</strong><strong>:</strong>&nbsp;</h3>



<p>A current gets induced in the coil when it is exposed to changing magnetic field. The magnetic field can be changed in various ways:&nbsp;</p>



<h3 class="wp-block-heading"><strong>Different ways to induce current:</strong>&nbsp;</h3>



<h4 class="wp-block-heading">1. <strong>Moving the magnet and keeping the coil at rest:</strong>&nbsp;</h4>


<div class="wp-block-image">
<figure class="aligncenter size-large"><img loading="lazy" decoding="async" width="1024" height="443" src="https://www.turito.com/learn-internal/wp-content/uploads/2022/08/fref-1024x443.png" alt="Magnet moving towards a stationary coil " class="wp-image-9486" srcset="https://www.turito.com/learn-internal/wp-content/uploads/2022/08/fref-1024x443.png 1024w, https://www.turito.com/learn-internal/wp-content/uploads/2022/08/fref-300x130.png 300w, https://www.turito.com/learn-internal/wp-content/uploads/2022/08/fref-768x332.png 768w, https://www.turito.com/learn-internal/wp-content/uploads/2022/08/fref.png 1169w" sizes="auto, (max-width: 1024px) 100vw, 1024px" /></figure></div>


<h4 class="wp-block-heading">2. <strong>Moving the coil and keeping the magnet at rest:</strong>&nbsp;</h4>



<figure class="wp-block-image size-large"><img loading="lazy" decoding="async" width="1024" height="444" src="https://www.turito.com/learn-internal/wp-content/uploads/2022/08/image-3224-1024x444.png" alt=" A coil moving towards a stationary magnet " class="wp-image-9268" srcset="https://www.turito.com/learn-internal/wp-content/uploads/2022/08/image-3224-1024x444.png 1024w, https://www.turito.com/learn-internal/wp-content/uploads/2022/08/image-3224-300x130.png 300w, https://www.turito.com/learn-internal/wp-content/uploads/2022/08/image-3224-768x333.png 768w, https://www.turito.com/learn-internal/wp-content/uploads/2022/08/image-3224.png 1168w" sizes="auto, (max-width: 1024px) 100vw, 1024px" /></figure>



<h4 class="wp-block-heading">3. <strong>Keeping the coils at rest and changing current in a coil:</strong>&nbsp;</h4>


<div class="wp-block-image">
<figure class="aligncenter size-full is-resized"><img loading="lazy" decoding="async" src="https://www.turito.com/learn-internal/wp-content/uploads/2022/08/rf.png" alt="3 Changing current in the coil " class="wp-image-9489" width="843" height="369" srcset="https://www.turito.com/learn-internal/wp-content/uploads/2022/08/rf.png 506w, https://www.turito.com/learn-internal/wp-content/uploads/2022/08/rf-300x131.png 300w" sizes="auto, (max-width: 843px) 100vw, 843px" /></figure></div>


<h4 class="wp-block-heading">4. <strong>Changing the area of a coil located in a magnetic field:</strong>&nbsp;</h4>


<div class="wp-block-image">
<figure class="aligncenter size-full is-resized"><img loading="lazy" decoding="async" src="https://www.turito.com/learn-internal/wp-content/uploads/2022/08/image-3225.png" alt="Changing area of the coil kept in magnetic field " class="wp-image-9269" width="853" height="371" srcset="https://www.turito.com/learn-internal/wp-content/uploads/2022/08/image-3225.png 508w, https://www.turito.com/learn-internal/wp-content/uploads/2022/08/image-3225-300x131.png 300w" sizes="auto, (max-width: 853px) 100vw, 853px" /></figure></div>


<h3 class="wp-block-heading"><strong>Motional Emf</strong>&nbsp;</h3>


<div class="wp-block-image">
<figure class="aligncenter size-full is-resized"><img loading="lazy" decoding="async" src="https://www.turito.com/learn-internal/wp-content/uploads/2022/08/image-3223.png" alt="Motional Emf " class="wp-image-9265" width="464" height="354" srcset="https://www.turito.com/learn-internal/wp-content/uploads/2022/08/image-3223.png 695w, https://www.turito.com/learn-internal/wp-content/uploads/2022/08/image-3223-300x229.png 300w" sizes="auto, (max-width: 464px) 100vw, 464px" /></figure></div>


<p>An Emf that is developed in a conductor because of relative motion in a magnetic field is known as motional Emf.&nbsp;</p>



<p>When a conductor moves in a magnetic field, the free electrons inside it experience a force and starts accumulating at the one end of the conductor, as a result, one end of the conductor becomes positively charged whereas the other end becomes negatively charged, and a potential difference is developed. This induced electric potential is known as motional emf.&nbsp;</p><div class="fillWidthInMob"><a loading='lazy' class="showAdInAllRes"  data-toggle="modal" data-target=#homeLeadForm data-heading="Get Expert Guidance" href="#"><img class="img-fluid" alt="parallel" src=https://a.storyblok.com/f/128066/1100x230/00b28b4876/11-applying-for-collages_leaderboard-1100x230.jpg /></a></div>


<div class="wp-block-image">
<figure class="aligncenter size-full is-resized"><img loading="lazy" decoding="async" src="https://www.turito.com/learn-internal/wp-content/uploads/2022/08/image-3235.png" alt="Motion of a conductor in a magnetic field " class="wp-image-9285" width="579" height="291" srcset="https://www.turito.com/learn-internal/wp-content/uploads/2022/08/image-3235.png 940w, https://www.turito.com/learn-internal/wp-content/uploads/2022/08/image-3235-300x151.png 300w, https://www.turito.com/learn-internal/wp-content/uploads/2022/08/image-3235-768x387.png 768w" sizes="auto, (max-width: 579px) 100vw, 579px" /></figure></div>


<h3 class="wp-block-heading"><strong>Factors on which motional Emf depend:</strong>&nbsp;</h3>



<ul class="wp-block-list">
<li>Motional Emf (E) increases with an increase in the magnetic field (B).&nbsp;</li>



<li>Motional Emf (E) increases with an increase in the velocity of the conductor (V).&nbsp;</li>



<li>Motional Emf (E) increases with an increase in the length of the conductor (L).&nbsp;</li>



<li>Motional Emf (E) also depends on the angle (θ) between V and B.</li>
</ul>



<h3 class="wp-block-heading"><strong>The formula for motional Emf (E):</strong>&nbsp;</h3>



<p>E α velocity of the conductor α V&nbsp;</p>



<p>E α Magnetic field α B&nbsp;</p>



<p>E α Length of the conductor α L&nbsp;</p>



<p>E α the angle (θ) between the in the conductor and the magnetic field (B), E α sinθ&nbsp;</p>



<p>E is maximum when θ = 90, E is minimum when θ = 0&nbsp;&nbsp;</p><div class="fillWidthInMob"><a loading='lazy' class="showAdInAllRes"  data-toggle="modal" data-target=#homeLeadForm data-heading="Get Expert Guidance" href="#"><img class="img-fluid" alt="parallel" src=https://a.storyblok.com/f/128066/1100x230/00b28b4876/11-applying-for-collages_leaderboard-1100x230.jpg /></a></div>



<p>Thus, E = BVL sinθ&nbsp;</p>



<p>When a moving conductor is placed in a magnetic field, an electric current is induced. This induced current is reversed if the conductor moves in the opposite direction or if the magnetic field is reversed. Thus, there is a relation between the direction of the conductor, magnetic field, and the current induced. There is a rule that can be used to know the relationship among them that is known as Fleming’s Right-hand rule.&nbsp;</p>



<h3 class="wp-block-heading"><strong>Fleming’s Right-Hand Rule</strong>&nbsp;</h3>



<p>According to Fleming’s Right-hand rule when the thumb, forefinger, and central finger are kept mutually perpendicular to each other then&nbsp;</p>


<div class="wp-block-image">
<figure class="aligncenter size-full is-resized"><img loading="lazy" decoding="async" src="https://www.turito.com/learn-internal/wp-content/uploads/2022/08/image-3226.png" alt="Fleming’s Right Hand Rule " class="wp-image-9271" width="392" height="376" srcset="https://www.turito.com/learn-internal/wp-content/uploads/2022/08/image-3226.png 802w, https://www.turito.com/learn-internal/wp-content/uploads/2022/08/image-3226-300x288.png 300w, https://www.turito.com/learn-internal/wp-content/uploads/2022/08/image-3226-768x737.png 768w" sizes="auto, (max-width: 392px) 100vw, 392px" /></figure></div>


<p><strong>Thumb</strong>&#8211; shows the direction of motion of the conductor&nbsp;</p>



<p><strong>Forefinger</strong>&#8211; shows the direction of the changing magnetic field</p>



<p>&nbsp;<strong>Middle finger</strong> – shows the direction of the induced current&nbsp;</p>



<h2 class="wp-block-heading">Summary</h2>



<ul class="wp-block-list">
<li>An emfis produced when there is a change in the magnetic flux linked to a closed circuit. This emf is called induced emf and the current produced is known as induced current </li>



<li>A current can be induced in the coil in various ways: . </li>



<li>By changing the strength of a magnetic field • </li>



<li>By changing the distance between the magnet and the conductor . </li>



<li>By changing the area of the loop located in the magnetic field. . </li>



<li>By changing current in a coil. </li>



<li>Motional EMF: An EMF that is developed in a conductor as a result of relative motion in a magnetic field is known as motional EMF </li>



<li>The formula for motional EMF </li>



<li>(E): E a velocity of the conductor a V </li>



<li>E a Magnetic field a B E a Length of the conductor a L</li>



<li> E a the angle (2) between the in the conductor and the magnetic field (B), F a sine</li>



<li>E is maximum when = 90, </li>



<li>E is minimum when = 0 Thus, E = BVL Sine Fleming&#8217;s Right-Hand Rule </li>



<li>According to Fleming&#8217;s Right-hand rule when the thumb, forefinger, and central finger are kept mutually perpendicular to each other then: </li>



<li>Thumb-shows the direction of motion of the conductor Forefinger-shows the direction of the changing magnetic field </li>



<li>Middle finger &#8211; shows the direction of the induced current</li>
</ul>
