Class 12th

When the electric charges moves, it creates attraction or repulsion. It creates magnetic forces and fields and called magnetism. The term "magnetism and matter" talks about the way magnetic forces and matter interact.

From ampere's circuital law

$?\stackrel{?}{B}.\stackrel{?}{dl}={\mu }_0{i}_{enc}$

$={\mu }_0\left(3+1\right)=4{\mu }_0$

The relation between $\alpha$ and $\beta$  is given as

$\beta =\frac{\alpha }{1-\alpha }$

${\beta }_1=\frac{\frac{20}{21}}{1-\frac{20}{21}}=20$

${\beta }_2=\frac{\frac{100}{101}}{1-\frac{100}{101}}=100$

$\stackrel{?}{F}=e{E}_0\stackrel{?}{j}$

${\stackrel{?}{a}}_y=\frac{e{E}_0}{m}\stackrel{?}{j}$

$=v_0\stackrel{?}{i}+\left(\frac{e{E}_{0}t}{m}\right)\stackrel{?}{j}$

$\left|\stackrel{?}{v}\right|=\sqrt[]{v_0^2+{\left(\frac{e{E}_{0}t}{m}\right)}^2}=v_0\sqrt[]{1+{\left(\frac{e{E}_{0}t}{m}\right)}^2}$

$\lambda =\frac{{\lambda }_0}{\sqrt[]{1+{\left(\frac{e{E}_{0}t}{m}\right)}^2}}$

From Lenz law, current in the square loop will be in anticlockwise sense.

Direction of  is perpendicular to equipotential surface.

For diamagnetic ; $\chi <0andl=\chi H$

At resonance V_L = V_C

_{$\Rightarrow cos?=\frac{V_R}{\sqrt[]{V_R^2+{\left(V_L-V_C\right)}^2}}=1$}

Density of nuclei is order of 10¹⁷ kg m^-3.

Photocell works on photoelectric effect.