Question

15) A positive ion passes through an electric and magnetic fields which are mutually perpendicular. The electric field strength is 20.0kV/m while the magnetic flux density is 0.40T. At what speed will the ion pass through undeflected?

a) 6.0×104
m/s

b) 5.0×104
m/s

c) 7.0×104
m/s
d) $8.0\times10^{4}$$m/s

16) For how long must a steady current of 2A flow through a copper voltameter to deposit 10À3 kg of copper? Z for coper is 0.000329g/C
a) 42.1min
b) 22.6min
c) 30.2min
d) 25.3min