Electric Charges and Fields

An electron falls from rest through a vertical distance h in a uniform and vertically upward directed electric field E. The direction of electric field is now reversed, keeping its magnitude the same. A proton is allowed to fall from rest in it through the same vertical distance h. The time of fall of the electron, in comparison to the time of fall of the proton is

• Smaller

• 5 times greater

• Equal

• 10 times greater

A square loop ABCD, carrying a current I₂, is placed near and coplanar with a long straight conductor XY carrying a current I₁, as shown in figure. The net force on the loop will be

• $\frac{{\mathrm{\mu }}_0 {\mathrm{I}}_1 {\mathrm{I}}_2}{2 \mathrm{\pi }}$

• $\frac{{\mathrm{\mu }}_0 {\mathrm{I}}_1{\mathrm{I}}_2 \mathrm{L}}{2 \mathrm{\pi }}$

• $\frac{2 {\mathrm{\mu }}_0 {\mathrm{I}}_1{\mathrm{I}}_2 \mathrm{L}}{3 \mathrm{\pi }}$

• $\frac{2{\mathrm{\mu }}_0 {\mathrm{I}}_1 {\mathrm{I}}_2}{3 \mathrm{\pi }}$

Two concentric conducting spherical shells A and B having radii r_A and r_B (r_B > rA) are charged to Q_A and -Q_B $\left(\left|{\mathrm{Q}}_{\mathrm{B}}\right| > \left|{\mathrm{Q}}_{\mathrm{A}}\right|\right)$ . The electric field along a line passing through the centre is

• $\left|{\mathrm{Q}}_{\mathrm{B}}\right| > \left|{\mathrm{Q}}_{\mathrm{A}}\right|$

• 

• 

•