 # Magnetic Effect of Current Formulae For NEET

When current is passed through the conductor it will produce a magnetic effect around it, so basically the wire acts like a magnet, and it will interact with the permanent magnet you have placed next to it, this effect can be reversed by changing the direction of the current, which according to the rule changes the direction of the magnetic field produced by it. 1. Magnetic field due to a moving point charge μo ≡ 4π × 10-7 N·s2/C2 is called the permeability of free space

2. Biot- savart’s Law: This law states that the magnetic field (dB) at point P due to small current element Idl of the current-carrying conductor is directly proportional to the Idl (current) element of the conductor  3. Magnetic field due to a straight wire  4. Magnetic field due to an infinite straight line  5. Magnetic field due to a circular loop i) At centre

B= μ0NI/2r

ii) At axis 6. Magnetic field on the axis of a solenoid B = (μ0NI/2) (cos θ1 – cos θ2)

7. Amperes Law 8. Magnetic field due to a long cylinder i) B= 0, r ＜ R

ii) B = μ0I/2πr, r ≥ R

9. Magnetic force acting on a moving point charge  10. Magnetic force acting on a current-carrying wire 11. Magnetic Moment of a current carrying loop

M = NIA

12. The torque acting on a loop 13. Magnetic field due to single pole

B = (μ0/2π) m/r2

14. Magnetic field on the axis of the magnet

B = (μ0/4π) 2M/r3

15. Magnetic field on the equatorial axis of the magnet

B = (μ0/4π) M/r3

16. Magnetic field at the point P of the magnet  