Current in the coil I 18 A The magnitude of the magnetic field a B H 21 B 10 x 2x16x RX 20 0 16 O is towards right i e East according to right hand The direction of magnetic field due to the coil x at centre thumb rule The magnitude of the magnetic field at the centre of coil y O expres clockwise the centre of coil x Mathematically 4RX10 T 21 10 x 2xx 18 x 25 0 1 4 Ty 1 2 9 x 10 T towards left i e West according to right hand thumb The direction of magnetic field due to coil y at centre O is rule Here the magnitude of B is greater than B so the resultant magnetic field will be in the direction of B i e left West 1 C 1 AMPERE S CIRCUITAL LAW According to this law the line integral of a magnetic field B around any closed path in vacuum is o times the net current Inet enclosed by the curve Boundary 1 2 TOPIC 2 Ampere s Circuital Law and Moving Surface 36 9 5f Bet Resultant is given tan d current Am always facil applied in field of a st discussed B d1 Honet Ampere s law is applicable only for an Amperian loop as the Gauss s law is used for Gaussian surface in electrostatics The choice of an Amperian loop has to be such that at each point of the loop either 1 B is tangential to the loop and is a non zero constant ii B is normal to the loop iii B vanishes Ampere s circuital law has same content as the Biot Savart s law Both of these relate magnetic field and current and Magn Straig Magneti distance taken as Ang Hen