Answer:
V = 6.55*10^{-6} v
Step-by-step explanation:
The number density can be determined by using below formula:

where,
B is uniform magnetic field 0.74
i is current 18 A
V is hall potential difference
l is thickness 150 MICRO METER
e is electron charge 1.6 *10^{-19} C
therefore V can be determined as


V = 6.55*10^{-6} v