# Physics - Tangent Law - Superposition of Magnetic Fields

**Tangent Law - Superposition of Magnetic Fields**

**Statement :**

** **When a magnetic needle is acted upon by two magnetic fields at right angles to each other, the needle will be deflected through an angle such that the tangent of the angle of deflection is equal to the ratio of the magnetic fields.

Mathematically,

**Explanation **

Let

and B be the earth's and applied magnetic field of induction which are perpendicular to each other.If a freely suspended magnetic needle is placed in these field, the needle comes to rest in the resultant field direction shown in figure.

If the needle makes an angle with earth's magnetic induction then

The above equation is called **Tangent Law.**