what factors limit the accuracy of a potentiometer and what was the objective of reversing the terminals of the cell

Explanation:

"The accuracy of a potentiometer can be increased by decreasing the potential gradient across the potentiometer wire, and this can be achieved by increasing the length"

The factors that are affecting/limiting the accuracy of the potentiometer are:

The objective of reversing the terminals of the cell

If the jockey of the potentiometer is pressed for a long time, joule heating sets in, so that reversing the terminals of the potentiometer will prevent the resistance due to joule heat from being added to the measured resistance, ultimately preventing unwanted resistance

force is based upon mass and acceleration.the statement is not always true.

it can be explained from newton's second law of motion.

as per newton's second law of motion the rate of change of momentum is directly proportional to the applied force and takes place along the direction of force.

mathematically it can be written as -

                                              ⇒      

here   k is the proportionality constant whose value is 1.

                                                            [a is the acceleration=dv/dt]

hence we see that force not only depends on mass and acceleration but also on velocity and rate of change of mass. force f will depend on mass and acceleration only when mass is constant.

hence the statement that force is based upon mass and acceleration is false.