Question

The field B at the centre of a circular coil of radius r is p times
that due to a long straight wire at a distance r from it, for
equal currents. Fig. shows three cases:
in all cases the circular part has radius r and straight ones are
infinitely long. For same current the field B at the centre P in
cases 1, 2, 3 has the ratio
(a) (- π/2):π/2:(3π/4 - 1/2)
(b) (- π/2 + 1):(π/2+ 1):(3π/4+ 1/2)
(c) - π/2:π/2:3π/4
(d) (- π/2 - 1):(π/4 + 1/4):(3π/4+ 1/2)

Answer 1

Answer:

The field B at the centre of a circular coil of radius r is p times

The field B at the centre of a circular coil of radius r is p timesthat due to a long straight wire at a distance r from it, for

The field B at the centre of a circular coil of radius r is p timesthat due to a long straight wire at a distance r from it, forequal currents. Fig. shows three cases:

The field B at the centre of a circular coil of radius r is p timesthat due to a long straight wire at a distance r from it, forequal currents. Fig. shows three cases:in all cases the circular part has radius r and straight ones are

The field B at the centre of a circular coil of radius r is p timesthat due to a long straight wire at a distance r from it, forequal currents. Fig. shows three cases:in all cases the circular part has radius r and straight ones areinfinitely long. For same current the field B