electromagnetism

Question 1

magnetic field

Answer 1

a current carrying conductor produces a magnetic field around it
the direction of the magnetic field of a current carrying wire is reversed when the direction of current is reversed
strength is increased when current is increased
use RHG
‘dot’ out of plane, ‘cross’ into the plane

Question 2

flat coil

Answer 2

strength of magnetic field of a flat coil can be increased by increasing the current flowing through the coil

Question 3

solenoid

Answer 3

magnetic field strength can be increased by
increasing the current flowing through the solenoid
increasing the number of turns per unit length of the solenoid
placing a soft iron core within the solenoid

Question 4

motor effect

Answer 4

when a current carrying conductor is placed in a magnetic field, the conductor experiences a force. this effect on the conductor is called the motor effect
the direction of the force on a current carrying conductor is reversed when we reverse the direction of the current or magnetic field
the force, current, and magnetic field are at right angle to one another
LHR

Question 5

force between two parallel current-carrying conductors

Answer 5

conductors carrying current in opposite directions repel

conductors carrying currents in the same direction attract

Question 6

force on a beam of charged particles in a magnetic field

Answer 6

positively charged particles move in the same direction as current
negatively charged particles move in the opposite direction as the current

Question 7

dc motor

Answer 7

spilt ring commutator is to reverse the direction of the current in the coil every half a revolution
when the coil is in vertical position, the current is cut off because the spilt ring commutator is not in contact with the carbon brushes. the direction of the currents flowing through the wire is now reversed