List of top Physics Questions on The Earth’s Magnetism

The equitorial magnetic field of earth on its surface at equator is $0.4\text{ G}$. Then its dipole moment is (The radius of the earth $R=6400\text{ km}$):
The magnetic susceptibility is negative for:
A dip needle vibrates in a vertical plane perpendicular to the magnetic meridian. The time period of vibration is
For a linear material, the relation between the relative magnetic permeability \( \mu_r \) and magnetic susceptibility \( \chi \) is:
The magnetic field at the centre of a circular coil having a single turn of the wire carrying current \( I \) is \( B \). The magnetic field at the centre of the same coil with 4 turns carrying the same current is:
A current carrying square loop is suspended in a uniform magnetic field acting in the plane of the loop. If \( \vec{F} \) is the force acting on one arm of the loop, then the net force acting on the remaining three arms of the loop is:
A moving coil galvanometer has 100 turns and each turn has an area of $2.0 \, \text{cm}^2$. The magnetic field produced by the magnet is $0.01 \, \text{T}$ and the deflection in the coil is $0.05$ radians when a current of $10 \, \text{mA}$ is passed through it. The torsional constant of the suspension wire is $x \times 10^{-5} \, \text{N} \cdot \text{m/rad}$. The value of $x$ is:
Paramagnetic substances:
A. align themselves along the directions of external magnetic field.
B. attract strongly towards external magnetic field.
C. has susceptibility little more than zero.
D. move from a region of strong magnetic field to weak magnetic field.
Choose the most appropriate answer from the options given below:
The horizontal component of earth’s magnetic field at a place is \( 3.5 \times 10^{-5} \, \text{T} \). A very long straight conductor carrying current of \( \sqrt{2} \, \text{A} \) in the direction from South East to North West is placed. The force per unit length experienced by the conductor is \( \ldots \times 10^{-6} \, \text{N/m} \).
The angle between magnetic meridian and geographical meridian is called
On suspending a magnet at 30° with the magnetic meridian, it makes an angle of 45° with the horizontal. What will be the actual angle of dip?
If the radius of the Earth is \( 6.4 \times 10^6 \, m \) and its magnetic dipole moment is \( 1.3 \times 10^{23} \, Am^2 \), then the magnetic field at the equator is:
A short bar magnet placed in a horizontal plane has its axis aligned along north-south direction. Null points are found on the axis of the magnet at \(20\ \text{cm}\) from the center of magnet. The earth's magnetic field at the place is \(B\) and angle of dip is \(0^\circ\). If the total magnetic field on the normal bisector of the magnet \(20\ \text{cm}\) from the center of the magnet is \(0.6\ \text{G}\), then the magnitude of \(B\) is:
The total intensity of earth's magnetic field at the poles is 7 units. Its value at the equator is