Answer:
When a wire that carries electrical current is placed in a magnetic field the wire experiences a force.
Explanation:
The electric motor is a device which convert electrical energy into mechanical energy ie when current carrying conductor is placed in magnetic field it experience a force. Flemings left hand rule explains the direction of the current.
The electric motor works by attraction and repulsion of magnetic field.
So the option d explains basic concept of simple motor ie when when current carrying wire is placed in the magnetic field it experience magnetic repulsive force.
1 coulomb of electric charge is carried by 6.25 x 10^18 electrons
1 Ampere = 1 coulomb per second
10 A = 10 coulombs per second
(2.0 x 10^20 electrons) x (coul / 6.25 x 10^18 electrons) / (10 coul/sec) =
(2.0 x 10^20) / (6.25 x 10^18 x 10) sec = <em>3.2 seconds</em>