The strength of a magnetic field is specified by the magnetic induction B or by the magnetic field strength H. A current I through a long, straight wire produces a magnetic field with strength H = I/2πr at a distance r from the wire. Given H = 1 A/m I = 10 A H = I/2πr 1 = 10/2πr r = 10/2π
Phosphorus (P) has 15 electron i.e 2,8,5. Hence the number of electron in its outermost orbit is 5. Silicon (Si) has 14 electron i.e 2,8,4. Hence the number of electrons in its outermost orbit is 4.
A DC motor can be operated from a single-phase AC supply. The direction of the torque produced by a DC machine is determined by the direction of current flow in the armature conductors and by the polarity of the field. Torque is developed in a DC machine because the commutator arrangement permits the field and armature currents to remain in phase, thus producing torque in a constant direction. A similar result can be obtained by using an AC supply, and by connecting the armature and field windings in series.
The emitter current (IE) of a transistor has two components such as base current (IB) and collector current (IC). The base current (IB) is about 2% of the emitter current (IE), but the collector current (Ia) is about 98% of the emitter current (IE). ∴ IE > IC > IB IE = IB + IC