Question

Question 3.17: What conclusion can you draw from the following observations on a resistor made of alloy manganin? Current A Voltage V Current A Voltage V 0.2 3.94 3.0 59.2 0.4 7.87 4.0 78.8 0.6 11.8 5.0 98.6 0.8 15.7 6.0 118.5 1.0 19.7 7.0 138.2 2.0 39.4 8.0 158.0

Class 12 - Physics - Current Electricity Current Electricity Page-129

Answer 1

according to Ohm's law, we know that Current passing through conductor is directly proportional to potential difference across the conductor . e.g., $V\proto\I$
or, V = IR , here R is proportionality constant . it is known as resistance of wire. higher the value of resistance , lower the current passing through the wire for same potential difference.

Here we got resistances by using Ohm's law,
$\bf{we\:conclude\:that\:ohms\:law}\\\bf{is \:valid \:to\:a\:high\:accuracy}\\\bf{resistance\:of the\:alloy\:is}\\\bf{nearly\:constant\:to\:all\:current.}$