An experiment was carried out to determine the electrical properties of a new conducting material. A bar was made out of the material, 18 cm long with a rectangular cross section 3 cm high and 0.8 cm...

An experiment was carried out to determine the electrical properties of a new conducting material. A bar was made out of the material, 18 cm long with a rectangular cross section 3 cm high and 0.8 cm deep. The bar was part of a circuit and carried a steady current (Figure 21.108 shows only part of the circuit). A uniform magnetic field of 1.5 tesla was applied perpendicular to the bar, coming out of the page (using some coils that are not shown).

(a) What is the sign of the mobile charges, and which way do they move? Explain carefully, using diagrams to support

your explanation.

(b) What is the drift speed v of the mobile charges? Explain your reasoning.

(c) What is the mobility u of the mobile charges?

(d) The current running through the bar was measured to be 0.6 ampere. If each mobile charge is singly charged

, how many mobile charges are there in 1 m3 of this material?

(e) What is the resistance in ohms of this length of bar?