When a 12 V battery is connected across an unknown resistor, there is a current of 2.5 mA in the circuit. Find the value of the resistance of the resistor.

A copper wire has diameter 0.5 mm and resistivity of 1.6 x 10^-8 m. What will be the length of this wire to make its resistance 10? How much does the resistance change if the diameter is doubled?

The values of current I flowing in a given resistor for the corresponding values of potential difference V across the resistor are given below:

I (amperes): 0.5 1.0 2.0 3.0 4.0

V (volts): 1.6 3.4 6.7 10. 2 13.2

Plot a graph between V and I plotted by using the given data is shown below:

A battery of 9 V is connected in series with resistors of 0.2, 0.3, 0.4 , 0.5 and 12 respectively. How much current would flow through the 12 resistor?

How many 176 resistors in parallel are required to carry 5 A on a 220 V line?