\(1.2 \times 10^{–5}\)
\(1.2 \times 10^{–3}\)
\(1.8 \times 10^{–3}\)
\(2.4 \times 10^{–5}\)
\(\vec{B'}\)=\(µ0(1-X)ni\) in the material
\(\vec{B}\)=µ0\(ni\) without material
So, fractional increase is
\(\frac{B'-B}{B} =X =1.2 × 10^{-5}\)
So, the correct option is (A): \(1.2 \times 10^{–5}\)
A conducting bar moves on two conducting rails as shown in the figure. A constant magnetic field \( B \) exists into the page. The bar starts to move from the vertex at time \( t = 0 \) with a constant velocity. If the induced EMF is \( E \propto t^n \), then the value of \( n \) is _____. 
A bar magnet has total length \( 2l = 20 \) units and the field point \( P \) is at a distance \( d = 10 \) units from the centre of the magnet. If the relative uncertainty of length measurement is 1\%, then the uncertainty of the magnetic field at point P is:

Given below are two statements:
Statement (I):
are isomeric compounds.
Statement (II):
are functional group isomers.
In the light of the above statements, choose the correct answer from the options given below:
The magnetic field is a field created by moving electric charges. It is a force field that exerts a force on materials such as iron when they are placed in its vicinity. Magnetic fields do not require a medium to propagate; they can even propagate in a vacuum. Magnetic field also referred to as a vector field, describes the magnetic influence on moving electric charges, magnetic materials, and electric currents.