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.
The factor by which, the induced E.M.F gets reduced due to short pitching is called pitch factor or coil span factor denoted by Kc. It is given as Kc = cosα/2 given α = 60° Kc = cos60/2 Kc = cos30° Kc = √3/2
The combined inductance of two coils connected in series L = L1 + L2 + 2M In series adding case L1 + L2 + 2M = 0.6 H ——–(1) In series opposing case L1 + L2 − 2M = 0.1 H ——–(2) Subtracting eqn (2) from eqn (1) we get 4M = 0.5 H M = 0.125 H Let L1 = 0.2 H (since the coil when isolated, its self-inductance is 0.2 H) Putting the value of M & L1 in equation (2) 0.2 + L2 + 2 ×0.125 = 0.06 0.2 + L2 = 0.35 L2 = 0.15 H
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