Acurrent of 3 a is running through a thin gold strip that is applied to an external magnetic field of 0.700 t. the length of the gold strip in the direction of the current is 40 mm, and the thickness of the strip, in the direction of the magnetic field, is 0.200 mm. the hall effect predicts that a potential difference can be measured between the two sides of the strips, which are 10 mm apart. (a) what is the average velocity of the electrons in the gold strip? assume that each gold atom contributes one electron. (b) what is magnitude of the electric field that is required to cancel the effect of the magnetic force that is acting on the on the moving electrons? (c) what is potential difference, or hall voltage, that can be measured between the sides of the gold strip? in the following, we will study how the parameters of our hall sensor affect the measured hall voltage. (d) by what factor does the hall voltage change if the strip is made of copper instead of gold? (e) how does the hall voltage change if we double the current? (f) how does the hall voltage change if we double the length of the strip? (g) how does the hall voltage change if we double the width of the strip? (h) how does the hall voltage change if we double the thickness of the strip?