A student measures the terminal potential difference V of a cell of emf and internal resistance r as a function of the current I flowing through it. Which of the following graphs will give the values of emf and internal resistance r ?

Step-by-step solution

The terminal potential difference V of a cell with emf and internal resistance r is given by the equation V = - Ir . This equation represents a linear relationship between V and I , which can be written in the form y = mx + c as V = -rI + . Comparing this with the equation of a straight line, the intercept on the V -axis (when I = 0 ) is , and the slope of the line is -r . Graph 1 shows V on the vertical axis and I on the horizontal axis with a negative slope, which matches the equation V = -rI + . The V -intercept