HARD
12th ICSE
IMPORTANT
Earn 100

A parallel plate air capacitor is charged to a certain potential difference. A dielectric plate is then inserted in the capacitor. In order to attain the initial potential difference, the charge on the plates has to be increased to three times. Determine the dielectric constant of the plate.

Important Questions on Capacitors and Dielectrics

HARD
12th ICSE
IMPORTANT
A slab of material of dielectric constant k has the same area as the plates of a parallel-plate capacitor but has a thickness 3d/4, where d is the plate separation. How is the capacitance changed when the slab is inserted between the plates?
MEDIUM
12th ICSE
IMPORTANT

A parallel-plate capacitor of capacitance C, with air between the plates, is shown in Fig. (a).
A sheet of dielectric constant K=5 is introduced between the plates so as to fill the space, as shown in Fig. (b). What are the values of the potential differences V1 and V2 across the plates in case (a) and (b) respectively? What are the charges Q1 and Q2 on the plates? In both cases, a battery of emf E is kept connected to the capacitor.

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HARD
12th ICSE
IMPORTANT
The distance between the plates of a capacitor is d. A metal plate of thickness d/2 is placed between the plates. What will be the effect on the capacitance? Explain.
MEDIUM
12th ICSE
IMPORTANT

A, B, C and D are four ‘thin’, similar metallic parallel plates, equally separated by distance d and connected to a cell of PD V as shown.

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Write the potentials at A, B, C and D.

MEDIUM
12th ICSE
IMPORTANT

A, B, C and D are four ‘thin’, similar metallic parallel plates, equally separated by distance d and connected to a cell of PD V as shown.

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If B and C be connected by a wire, then what will be the potentials of the plates?

HARD
12th ICSE
IMPORTANT

A, B, C and D are four ‘thin’, similar metallic parallel plates, equally separated by distance d and connected to a cell of PD V as shown.

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How will the electric fields change in the spacings between the plates ?

MEDIUM
12th ICSE
IMPORTANT

A, B, C and D are four ‘thin’, similar metallic parallel plates, equally separated by distance d and connected to a cell of PD V as shown.

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Will the charges on the plates A and D change?

MEDIUM
12th ICSE
IMPORTANT

A capacitor of capacitance C is charged up to a potential difference V. After removing the charging battery, the capacitor is connected in parallel with an uncharged capacitor of the same capacitance. What will be the effect on potential difference of first capacitor in this case.