Materials Required

• Coil 
• Galvanometer 
• Connecting wires 
• Magnet 
• Rheostat 
• Key 
• Insulator like glass sheet or cardboard  
• Cell 

 

The Procedure

 Real Lab Procedure

1. A magnet towards and away from it

• Connect 100 turns coil to sensitive galvanometer.
• Hold magnet towards the coil.  
• observe some deflection of the galvanometer needle. 
• Move the magnet away from the coil with roughly the same speed as it moves towards the coil. You will observe the same deflection, but now in opposite direction. 
• Repeat procedures with different speeds. 

2.Demonstrating production of induced emf in a coil due to the movement of similar coil carrying current towards and away from it. 

• Connect coil of 100 turns to sensitive galvanometer. 
• Take another coil of 50 turns. 
• Connect 50 turns coil to the lower end of rheostat. 
• Connect the upper end of rheostat to key. 
• Connect the key to the negative terminal of the cell. 
• Connect positive side of battery to 50 turns coil.  

a) Production of induced emf by moving coil towards or away from another coil 

• Close key. 
• Move the 50 turns coil towards 100 turns coil.
• Move the 50 turns coil away from the 100 turns coil with same speed. 
• Repeat the experiment with different speeds. 
• Place 50 turns coil at a closer distance from 100 turns coil.

b) Production of induced emf by Changing current 

• Close key. 
• Change current through 50 turns coil using rheostat. 
• Observe what happens in galvanometer. 

c)Production of induced emf by Opening and closing key and changing common area between the coils 

• Place 50 turns coil on 100 turns coil separated by glass sheet. 
• Close the key. 
• Open the key. 
• Observe what happens when we open and close the key. 
• Close key.  
• Slide 50 turns coil on glass sheet as common area between the 50 turns coil and 100 turns coil decreases. 
• Observe what happens.  
• Slide 50 turns coil on glass sheet as common area between the 50 turns coil and 100 turns coil decreases. 
• Observe what happens. 

 Simulator Procedure 

• Show the first experiment-A magnet towards and away from it. 
• Click on the check box to show/hide the circuit diagram and connect the circuit.  
• Drag and drop the wire from the 100 turns coil to positive terminal of galvanometer to connect it.  
• Drag and drop the wire from the other end of 100 turns coil to negative terminal of galvanometer to connect it.  
• Click on magnet A. 
• Select the speed of magnet using slider.  
• Click on the magnet to move the magnet towards the coil.  
• Click on the magnet to move the magnet away from the coil.  
• Repeat procedures with different speeds. 
• Click on magnet B. 
• Repeat the above procedure with Magnet B. 
• Click on the Inference button to show the observation.  
• Click on the Next button.  
• Show the second experiment - Similar coil carrying current towards and away from it.  
• Click on the check box to show/hide the circuit diagram and connect the circuit.  
• Drag and drop the wire from the 100 turns coil to one end of galvanometer to connect it.  
• Drag and drop the wire from the 100 turns coil to another end of galvanometer.  
• Drag and drop the wire from the 50 turns coil to lower end of Rheostat.  
• Drag and drop the wire from the key to upper end of Rheostat.  
• Drag and drop the wire from the –ve end of the cell to another end of the key.  
• Drag and drop the wire from the +ve end of the cell to 50 turns coil.    
• Select the experiment from the drop-down list.      

a) Moving Coil 

• Drag and drop the key into the key holder.  
• Select the speed of 50 turns coil using slider.  
• Click on the 50 turns coil to move towards the 100 turns coil.  
• Click on the 50 turns coil to move away from the 100 turns coil.  
• Repeat procedures with different speeds. 
• Click on the Inference button to show the observation.  

b) Changing Current

• Drag and drop the key into the key holder. 
• Click the Move Slider button to move the rheostat slider on the right side.  
• Click the Move Slider button to move the rheostat slider on the left side.  
• Click on the Inference button to show the observation. 

c) Changing Current & Area 

• Click the glass plate and place it on the 100 turns coils. 
• Click the 50 turns coil and place it on the glass plate. 
•  Drag and drop the key into the key holder. 
• Click on the Inference button to show the observation.  
• Drag and drop the key outside the key holder. 
• Click on the Inference button to show the observation.   
• Click on the Next button.  
• Drag and drop the key into the key holder. 
• Click on the 50 turns coil and move on the glass plate as the common area decreases. 
• Click on the 50 turns coil and move on the glass plate as the common area increases. 
• Click on the Inference button to show the observation. 

Observation 

• When we bring magnet towards or away from the coil, pointer in galvanometer deflects. Deflection in the galvanometer increases with the speed of magnet.
• When we move 50 turns coil towards 100 turns coil, pointer in the galvanometer deflects. As the speed of the 50 turns coil changes, the deflection of the pointer in the galvanometer changes.
• The pointer in the galvanometer deflects when the current through the 50 turns coil changes.
• When we close or open the key the pointer in the galvanometer deflects. 
• When we change the common area between the coils, the pointer on the galvanometer deflects.

 

Conclusion 

When magnetic flux through a coil changes an emf induces in that coil.