Explanation:
It is given that,
Mass of lithium, 
It is accelerated through a potential difference, V = 224 V
Uniform magnetic field, B = 0.724 T
Applying the conservation of energy as :


q is the charge on an electron

v = 78608.58 m/s

To find the radius of the ion's path in the magnetic field. The centripetal force is balanced by the magnetic force as :



r = 0.0078 meters
So, the radius of the path of the ion is 0.0078 meters. Hence, this is the required solution.
Answer:
The induced voltage in the coil is 0.25 V.
Explanation:
It is given that,
Area of a square coil is 2 cm or 0.02 m
Number of turns in the wire is 2500
A uniform magnetic field perpendicular to its plane is turned on and increases to 0.25 T during an interval of 1.0 s.
We need to find the induced voltage in the coil. According to Faraday's law, the induced emf in the coil is given by the rate of change on magnetic flux. So,

So, the induced voltage in the coil is 0.25 V.
Magnetic force:Computer hard drives use magnetism to store the data on a rotating disk. More complex applications include: televisions, radios, microwave ovens, telephone systems, and computers. ... Frictional force:Quite often uses of friction can be seen from how things would be without friction.