A. 1/4

B. 1/2

C. 1

D. 2

When a dielectric slab of the same area of cross-section and thickness equal to 2/3 of the separation is introduced between the plates of a parallel plate capacitor, its capacitance becomes 2.25 times the original value. The dielectric constant of the material of the slab is

A charge of 10 units is divided so that force between the two charges is maximum when placed 2cm apart. The two charges are

A condenser of 20μF is charged to a certain voltage and then discharged through a 4x10^{6}Ω resistor.The time taken for the condenser to lose 63% of its charge is

The charge stored in a capacitor is 20μC and the potential difference across the plates is 500V,its capacity is

Two spheres of radii 12 cm and 16 cm have equal charge. The ratio tstored in the condenser is