In comparing wires of identical shape and carrying the same current but made of different metals, is the drift velocity in each wire inversely proportional to the number density of charge carriers? No. The drift velocity is directly proportional to the number density of carriers . No. The drift velocity is the same for all conductors. Yes. To have the same current from k times as many carriers, it takes k times the drift speed. Yes. To have the same current from k times as many carriers, it takes 1/k times the drift speed.

a. are

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.