Question

Which of the following can be determined by Hall effect?
A. The electron specific heat at constant volume per electron,
B. The sign of the current carrying charges,
C. The temperature of a rectangular metal slab,
D. The charge density, E. The mobility of the charge carriers.

• A. A, C and D Only
• B. B, D and E Only
• C. B, C and E Only
• D. C, D and E Only

Hint:

Hall effect helps determine carrier type, carrier concentration and mobility.

Answer 1

The Correct Option is B

Concept:
Hall effect is used to study the nature and concentration of charge carriers in a conductor or semiconductor.

Step 1: Sign of charge carriers.
The sign of Hall coefficient tells whether charge carriers are electrons or holes. \[ B \text{ is correct} \]

Step 2: Charge density.
For a single carrier type: \[ R_H=\frac{1}{ne} \] Thus, charge carrier density can be found. \[ D \text{ is correct} \]

Step 3: Mobility.
Mobility can be found using Hall coefficient and conductivity. \[ \mu=\sigma R_H \] So, \[ E \text{ is correct} \]

Step 4: Final selection.
The correct statements are: \[ B,D,E \] \[ \therefore \text{Correct Answer is (B)} \]