Advertisements
Advertisements
प्रश्न
A capacitor of capacitance ‘C’ is charged to ‘V’ volts by a battery. After some time the battery is disconnected and the distance between the plates is doubled. Now a slab of dielectric constant, 1 < k < 2, is introduced to fill the space between the plates. How will the following be affected? (a) The electric field between the plates of the capacitor Justify your answer by writing the necessary expressions.
उत्तर
The electric field between the plates is
`E=V/D`
The distance between plates is doubled, d' = 2d
`E'=(V')/(D')=(V/K)xx1/(2d)=1/2(E/K)`
Therefore, if the distance between the plates is double, the electric field will reduce to one half.
APPEARS IN
संबंधित प्रश्न
Define capacitor reactance. Write its S.I units.
The capacitance of a capacitor does not depend on
Find the equivalent capacitance of the system shown in figure between the points a and b.
Find the capacitance of the combination shown in figure between A and B.
The two square faces of a rectangular dielectric slab (dielectric constant 4⋅0) of dimensions 20 cm × 20 cm × 1⋅0 mm are metal-coated. Find the capacitance between the coated surfaces.
An air-filled parallel-plate capacitor is to be constructed which can store 12 µC of charge when operated at 1200 V. What can be the minimum plate area of the capacitor? The dielectric strength of air is `3 xx 10^6 "Vm"^-1`
The variation of inductive reactance (XL) of an inductor with the frequency (f) of the ac source of 100 V and variable frequency is shown in fig.
(i) Calculate the self-inductance of the inductor.
(ii) When this inductor is used in series with a capacitor of unknown value and resistor of 10 Ω at 300 s–1, maximum power dissipation occurs in the circuit. Calculate the capacitance of the capacitor.
Obtain the expression for capacitance for a parallel plate capacitor.
Calculate the resultant capacitances for each of the following combinations of capacitors.
Two similar conducting spheres having charge+ q and -q are placed at 'd' seperation from each other in air. The radius of each ball is r and the separation between their centre is d (d >> r). Calculate the capacitance of the two ball system ______.