PUMPA - SMART LEARNING

எங்கள் ஆசிரியர்களுடன் 1-ஆன்-1 ஆலோசனை நேரத்தைப் பெறுங்கள். டாப்பர் ஆவதற்கு நாங்கள் பயிற்சி அளிப்போம்

Book Free Demo
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Electric circuit to study the factors on which the resistance of conducting wires depends
  1. Complete an electric circuit consisting of a cell, an ammeter, a nichrome wire of length \(l\) [say, marked (\(1\))] and a plug key, as shown in figure.
  2. Now, plug the key. Note the current in the ammeter.
  3. Replace the nichrome wire by another nichrome wire of same thickness but twice the length, that is \(2l\) [marked (\(2\)) in the figure].
  4. Note the ammeter reading.
  5. „Now replace the wire by a thicker nichrome wire, of the same length \(l\) [marked (\(3\))]. A thicker wire has a larger cross-sectional area. Again note down the current through the circuit.
  6. Instead of taking a nichrome wire, connect a copper wire [marked (\(4\)) in figure] in the circuit. Let the wire be of the same length and same area of cross-section as that of the first nichrome wire [marked (\(1\))]. Note the value of the current.
  7. Notice the difference in the current in all cases.
Does the current depend on the length of the conductor?
 
, the current value  when the length of the wire is . The ammeter reading is when a thicker wire of the same length and material is used.
 
Does the current depend on the area of cross-section of the wire used?
  
, the ammeter reading when a wire of different materials with the same area of cross-section is used.