Origin of Magnetic Field

Q. Where does the magnetic force originate?

1. Ferromagnetic materials like iron.
2. The earth's North and South Pole.
3. The centre of the Universe.
4. The motion of electrons in atoms.

Q. Lodestone, which had magnetic properties was apparently first found where?

1. Magnesia, Greece
2. Magnetica, Italy
3. Magnemon, Turkey
4. New York, USA

Q. An ionized gas contains both positive and negative ions. If it is subjected simultaneously to an electric field along the +x direction and a magnetic field along the +z direction, then

1. Positive ions deflect towards +y direction and negative ions towards –y direction
2. All ions deflect towards +y direction
3. All ions deflect towards –y direction
4. Positive ions deflect towards –y direction and negative ions towards +y direction

Q. A magnetic field can be produced by

1. A moving charge
2. A changing electric field
3. None of these
4. Both moving charge & changing electric field

Q. Magnitude of surface charge density on each plate of a parallel plate capacitor is $88.5\mu {\text{C/m}}^2$. What is the magnitude of the electric field in the region between the plates?
(Take ${ϵ}_o=8.85\times {10}^{-12}{\text{C}}^2{\text{/N m}}^2$)

1. ${10}^7\text{N/C}$
2. ${10}^6\text{N/C}$
3. $2\times {10}^7\text{N/C}$
4. $4\times {10}^7\text{N/C}$

Q. 23.An electron is moving with speed 2x10^{​5 m/s} along the positive x-direction in the presence of magnetic induction
B=i+4j-3k. The magnitude of the force experienced by the electron in N (e=1.6x19^-19 C)

Q. Magnetic field lines appear to move from the South pole towards the North pole inside a magnet.

1. True
2. False

Q. An electron is revolving around a proton in a circular orbit of radius $\frac{1}{2}{A}^{\circ }$. If it produces a magnetic field of 14 T, its angular velocity in rad/s

1. $4\times {10}^{16}$
2. $4\times {10}^{-15}$
3. $4\times {10}^{17}$
4. $4\times {10}^{18}$

Q. Dimensional formula for intensity of magnetising field and magnetic susceptibility are.

1. $\left[M^{0}A{L}^{-1}{T}^0\right]\left[M^0{A}^0{L}^0{T}^0\right]$
2. $\left[M^0{A}^2{L}^{-1}{T}^2\right]\left[M^{0}AL{T}^{-1}\right]$
3. $\left[M^0{A}^1{L}^{-1}{T}^2\right]\left[M^0{A}^0{L}^0{T}^0\right]$
4. $\left[ML{T}^{-2}\right]\left[M{L}^2{T}^{-2}\right]$