201.

Five capacitors, each of capacitance value C are connected as shown in the figure. The ratio of
capacitance between P and R, and the capacitance between P and Q is

    

• 3 : 1

• 5 : 2

• 2 : 3

• 1 : 1

Two infinitely long parallel conducting plates having surface charge densities + σ and $-$σ  respectively, are separated by a small distance. The medium between the plates is vacuum. lf ε₀ is the dielectric permittivity of vacuum, then the electric field in the region between the plates is

• 0 volt/metre

• $\frac{\mathrm{\sigma }}{2{\mathrm{\epsilon }}_{\mathrm{o}}}$ volt/metre

• $\frac{\mathrm{\sigma }}{{\mathrm{\epsilon }}_{\mathrm{o}}}$ volt/metre

• $\frac{2\mathrm{\sigma }}{{\mathrm{\epsilon }}_{\mathrm{o}}}$ volt/metre

Two concentric conducting thin spherical shells  A  and  B  having radii r_A and  r_B  ( r_B > r_A ) are charged to Q_A and - Q_B  (). The electrical field along a line, (passing through the centre is)

Four point + ve charges  of same magnitude (Q)  are placed at four corners of  a rigid square frame as shown in figure. The plane of the frame is perpendicular to Z-axis. If a -ve point charge is placed at a distance z away from the above frame ( z < < l ) then

• -ve charge oscillates along the Z-axis

• it moves away from the frame

• it moves slowly towards the frame and stays in the plane of the frame

• it moves slowly towards the frame and stays in the plane of the frame

Equipotential surfaces associated with an electric field which is increasing in magnitude along the x-direction are

• planes parallel to yz - plane

• planes parallel to xz-plane

• planes parallel to xz-plane

• coaxial cylinders of increasing radii around  the x-axis

A 40F capacitor in a defibrillator is charged to 3000 V. The energy stored in the capacitor is sent through the patient during a pulse of duration 2 ms. The power delivered to the patient is

• 45 kW

• 90 kW

• 180 kW

• 360 kW

In the basic CsCl crystal structure, Cs⁺ and Cl^- ions are arranged in a bcc configuration as shown in the figure. The net electrostatic force exerted by the eight Cs^- ions on the Cl^- ion is

• $\frac{1}{4{\mathrm{\pi \epsilon }}_{\mathrm{o}}} \frac{4{\mathrm{e}}^2}{3{\mathrm{a}}^2}$

• $\frac{1}{4{\mathrm{\pi \epsilon }}_{\mathrm{o}}} \frac{16{\mathrm{e}}^2}{3{\mathrm{a}}^2}$

• $\frac{1}{4{\mathrm{\pi \epsilon }}_{\mathrm{o}}} \frac{32{\mathrm{e}}^2}{3{\mathrm{a}}^2}$

• zero

An electron is travelling along the x-direction. It encounters a magnetic field in the y-direction. Its subsequent motion will be

• straight line along the x-direction

• a circle in the xz plane

• a circle in the yz plane

• a circle in the xy plane

An electron having charge 'e' and mass m is moving in a uniform electric field E. Its acceleration will be

• $\frac{{\mathrm{e}}^2}{\mathrm{m}}$

• $\frac{\mathrm{eE}}{\mathrm{m}}$

• $\frac{{\mathrm{eE}}^2}{\mathrm{m}}$

• $\frac{\mathrm{mE}}{\mathrm{e}}$

In the given figure, the capacitance C₁,  C₃,  C₄ and  C₅ have  a capacitance 4 μF each. If the capacitor  C₂ has a capacitance 10 μF, then effective capacitance between A and B will be

• 2 μF

• 6 μF

• 4 μF

• 8 μF