Study the VI graph for a resistor as shown in the figure and prepare a table showing the values of I (in amperes) corresponding to four different values of V (in volts). Find the value of current for V = 10 volts.
How can we determine the resistance of the resistor from this graph?

Asked by harjot.arshleen | 21st May, 2021, 06:48: PM

Expert Answer:

Graph shows the relation between Voltage and current is linear.  Voltage is directly proportional to Current .
 
Let us assume a relation,   V = k I  ..........................(1)
 
where V is voltage , I is current and k is constant .
 
From graph , we get voltage V = 4 Volt when current I is 2 A .
 
By substituting these voltage and current in eqn.(1) , we get k = 2
 
Hence relation between Voltage and current ,  V =  2 × I     or    I  = 0.5 V  ...........................(2)
 
Following table shows current for different voltage
 
Voltage V ( Volt )  Current I ( A)
2 1
4 2
6 3
8 4
10 5

 

 
 
 
 
 
 
 
From table we see that at voltage 10 V ,  current I = 5 A
 
Resistance = Voltage / Current
 
From eqn.(2) , we get , Resistance = V / I = 2 Ω

Answered by Thiyagarajan K | 21st May, 2021, 08:22: PM