AP EAMCET2013PhysicsMagnetic Properties of Matter
A deflection magnetometer is adjusted and a magnet of magnetic moment M is placed on it in the usual manner and the observed deflection is . The period of oscillation of the needle before settling of the deflection is T . When the magnet is removed, the period of oscillation of the needle is T₀ before settling to 0^ -0^ . If the earth's induced magnetic field is B_H , the relation between T and T₀ is
Options
- AT^2=T₀^2
- BT^2= T₀^2
- CT=T₀
- DT= T₀
Correct answer
A. T^2=T₀^2
Step-by-step solution
In deflection magnetometer, field due to magnet F and horizontal component B_H of earth's field are perpendicular to each other. Net field is F^2+B_H^2 So the time period T=2 1 M F^2+B_H When magnet is removed T₀=2 1 M B_H Also, F B_H = Dividing Eqs. (i) by (ii), we get aligned T T₀ & = B_H F^2+B_H^2 & = B_H B_H^2+ ^2 +B_H^2 = B_H B_H ^2 & = T^2 & =T₀^2 aligned