A) Nearly 3 x109 m/s
C) Independent of current strength
D) The same as propagation velocity of electric energy
A) Nearly 3 x109 m/s
C) Independent of current strength
D) The same as propagation velocity of electric energy
A) A voltage source, a resistor and a switch
B) A voltage source and a conductor
C) A power source and a bulb
D) A voltage source, a conductor, an ammeter and a switch
A) Electrons only
B) Positive and negative ions
C) Electrons and positive ions
A) Random movement of electrons in a conductor
B) Movement of free electrons predominately in one direction
C) pressure difference between two poles
D) the power that causes drift of electrons.
B) Increases armature speed
C) Reduces interpoles flux density
D) Results in sparking trouble