20 Physics -- Capacitor

Define dielectric. A dielectric is present in between two plates of a capacitor.

0 Answers

Why the capacitor stores energy but not charge??

First of all, let's know what really storing anything means. To store something implies there should be presence of some extra amount of it in them. Like same storage of energy or charge in any system implies the net charge or energy in the system is not equal to zero.

Now let's consider a parallel plate capacitor in which the plate connected to the positive terminal of a battery gets positive charge and induces same amount of negative charge on the another plate. So the total net charge...

Batteries are always labeled with their emf, would it also be appropriate to put a label on batteries stating how much current they provide? Why or why not?

Ans: No, a battery does not always produce the same current, no matter what circuit it’s used in. The current in any electric circuit consisting of a cell of emf E and internal resistance r and an external resistance R is given by

I = E/(R + r)

This equation shows that the current that asourceof emf produces in a given circuit depends on the external resistance R as well as the internal resistance r of the cell. The greater the resistance, the less current thesourcewill produce. So, however, a...

Find the equivalent capacitance of five capacitor networks shown below.

Prove that :Electric field intensity(E)= potential difference (V)/distance between two plates(d)i.e. E=V/d

V=W/q

V=Fd/q

V=F/q*d

V=E.d [E=F/q]

E=V/d

Is it suitable to use capacitor of capacitance 1 Farad in our house? Why? Why not?

Explain the difference between polar and non-polar dielectrics with one example of each .

Polar Dielectric:

1. Contains polar molecules that have permanent electric dipole moments.

2. When an electric field is applied, the polar molecules align themselves with the field.

3. Examples: Water (H2O), ammonia (NH3), and hydrogen fluoride (HF).

Non-Polar Dielectric:

1. Consists of non-polar molecules that lack permanent electric dipole moments.

2. They do not align with an applied electric field.

3. Examples: Carbon dioxide (CO2), methane (CH4), and oxygen (O2).

The key difference is that polar...

A capacitor has a vacuum in the space between the conductor plates. If you double the charge on each conductor, what happens to the capacitance?

When charge is given to a capacitor thepotential difference across its plates rises. Asthe more and more charge is given, itspotential increases accordingly. If a charge Qis given to the capacitor so that its potentialrises through V, then it has been found thatcharge Q stored in it is directly proportional topotential difference V across the plates of thecapacitor. So,

Q V

Q = CV

where C is a proportionality constant, calledthe capacitance of the capacitor. Its valuedepends upon the shape and...

Q) During lighting, it is safest to sit inside a car rather than near a tree. Why?

Q) Can it be possible to place a parallel plate capacitor of one farad capacity in our house?

Q) Separation between the plates of a capacitor is increased after disconnecting from battery, what happens to the potential difference across the capacitor?

Q) Two identical capacitors are connected in series. Is the resulting capacitance greater or less than that of individual capacitor?

Q) The spherical dome on a Van de Graff generator is placed near an earthed metal plate. The dome has a diameter of 40 cm and the potential at it's surface is 54 kV.i) Calculate the charge on the d...

Q) Three capacitors each of 6μF are connected together in series and then connected in series with the parallel combination of three capacitors of 2μF,4μF and 2μF. Find the effective capacitance in...

Q) A parallel plate capacitor has square plates of side 5 cm and separated by a distance of 1 mm. (a) Calculate the capacitance of this capacitor. (b) If a 10 V battery is connected to the capacito...

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