# Capacitance of Parallel Plate Capacitor

## Trending Questions

**Q.**

A simple pendulum is suspended from the roof of a trolley which moves in a horizontal direction with an acceleration *a*, then the time period is given by T=2π√lg′ , * *where g is equal to

g

g-a

g+a

**Q.**A parallel plate air capacitor is charged to a potential difference of V volt. After disconnecting the charging battery, the distance between the plates of the capacitor is increased using an insulating handle. As a result, the potential difference between the plates

- Decreases
- Does not change
- Becomes zero
Increases

**Q.**

A capacitor $C$ is fully charged with voltage ${V}_{0}$. After disconnecting the voltage source, it is connected in parallel with another uncharged capacitor of capacitance C/2. The energy loss in the process after the charge is distributed between the two capacitors is:

$\frac{1}{2}C{{V}_{0}}^{2}$

$\frac{1}{4}C{{V}_{0}}^{2}$

$\frac{1}{3}C{{V}_{0}}^{2}$

$\frac{1}{6}C{{V}_{0}}^{2}$

**Q.**In an AC circuit, an alternating voltage, V=200√2sin(100t), is connected to a capacitor of capacitance 1 μF. The rms value of the current in the circuit is -

- 10 mA
- 30 mA
- 40 mA
- 20 mA

**Q.**A large sheet carries uniform surface charge density σ. A rod of length l has linear charge density λ on one half and −λ on the second half. The rod is hinged at mid-point O and makes an angle θ with the normal to the sheet. The torque experienced by the rod is

- Zero
- σλl28ϵ0sinθ
- σλl2ϵ0sinθ
- σλl22ϵ0

**Q.**.A dielectric slab of dielectric constant K is placed between the plates of a parallel plate capacitor carryingcharge q. The induced charge q on the surface of slab is given by(1)q=q-q/K (2)q=-q+q/K (3)q=q(1/K+1) (4)q=-q(1+1/K)

**Q.**A 50 W, 100 V lamp is to be connected to an AC mains of 200 V, 50 Hz. What capacitance is essential to be put in series with the lamp?

- 1 μF
- 2 μF
- 4.2 μF
- 9.2 μF

**Q.**Two capacitors C1 and C2 are charged to 120V and 200V respectively. It is found that by connecting them together the potential on each one can be zero. Then A 3C1 + 5C2 = 0 B 9C1 + 4C2 = 0 C. 5C1=3C2 D 3C1=5C2

**Q.**Two parallel, long wires carry currents i1 and i2 with i1>i2. When the currents are in the same direction, the magnetic field at a point mid way between the wires is 10μT. If the direction of i2 is reverse, the field become 30μT. The ratio i1i2 is

- 4
- 2
- 3
- 1

**Q.**

A composite slab consists of two slabs A and B of different materials but of the same thickness placed one on top of the other. The thermal conductivities of A and B are k1 and k2 respectively. A steady temperature difference of 12∘C is maintained across the composite slab. If k1=k22, the temperature

**Q.**A simple pendulum of length \(L\) is placed between the plates of a parallel plate capacitor having electric field \(E\), as shown in figure. Its bob has mass \(m\) and charge \(q\). The time period of the pendulum is given by :

bbb bbb

**Q.**In an LCR series circuit, an inductor 30 mH and a resistor 1 Ω are connected to an AC source of angular frequency 300 rad/s. The value of capacitance for which, the current leads the voltage by 45∘ is 1x×10−3 F. Then the value of x is ______.

**Q.**

A parallel-plate capacitor has plate area 25.0 cm2 and a separation of 2.00 mm between the plates. The capacitor is connected to a battery of 12.0 V. (a) Find the charge on the capacitor. (b) The plate separation is decreased to 1.00 mm. Find the extra charge given by the battery to the positive plate.

**Q.**In the given figure, if each plate has area A and separation between plates is d, then equivalent capacitance between A & B is

- 25ε0Ad
- 52ε0Ad
- 32ε0Ad
- ε0Ad

**Q.**Capacitance of a parallel plate capacitor depends upon which of its following attributes?

- Charge
- Potential difference
- Size of the plates
- Separation between the plates

**Q.**A parallel plate capacitor has a dielectric slab of dielectric constant K between its plates that covers 1/3 of the area of its plates, as shown in the figure. The total capacitance of the capacitor is C while that of the portion with dielectric in between is C1. When the capacitor is charged, the plate area covered by the dielectric gets charge Q1 and the rest of the area gets charge Q2. The electric field in the dielectric is E1 and that in the other portion is E2. Choose the correct option/options, ignoring edge effects.

- CC1=2+KK
- E1E2=1K
- Q1Q2=3K
- E1E2=1

**Q.**Consider the force F on a charge ′q′ due to a uniformly charged spherical shell of radius R carrying charge Q distributed uniformly over it. Which one of the following statements is true for F, if ′q′ is placed at distance r from the centre of the shell?

- F=14πε0QqR2 for r<R
- 14πε0QqR2>F>0 for r<R
- F=14πε0Qqr2 for r>R
- F=14πε0QqR2 for all r

**Q.**24. Consider a metal sphere of radius R that is cut in two parts along a plane whose minimum distance from the spheres centre is h. Sphere is uniformly charged by a total electric charge Q. The minimum force necessary to hold the two parts of the sphere together is ?

**Q.**

Two small charged spheres A and B have charges of $10\text{\mu C}$ and $40\text{\mu C}$ respectively and are held at a separation of $90\text{cm}$ from each other. At what distance from A, electric field intensity would be zero?

$22.5\text{cm}$

$18\text{cm}$

$30\text{cm}$

$36\text{cm}$

**Q.**A dielectric slab of dielectric constant K is placed between plates of parallel plate capacitor carrying charge q . the induced q charge on the surface of slab is given by ?

**Q.**Consider two spherical shells of radius R1 and R2 respectively with charges Q1 and Q2 respectively. find electric field at a distance r(R1, R2

**Q.**

Find the potential difference between the points A and B and between the points B and C of figure (32-E33) in steady state.

Figure 32-E33

**Q.**A capacitor, made of two parallel plates each of plate area A and separation d, being charged by an external AC source. Show that the displacement current inside the capacitor is same as the current charging the capacitor.

**Q.**At a place the value of horizontal component of the earth's magnetic field H is 3×10−5Weber/m2 . A metallic rod AB of length 2 m placed in east-west direction, having the end A towards east, falls vertically downward with a constant velocity of 50 m/s. Which end of the rod becomes positively charged and what is the value of induced potential difference between the two ends

- End A, 3 mV
- End A, 3×10−3mV
- End B, 3×10−3mV
- End B, 3 mV

**Q.**

Hall effect is used to measure?

**Q.**Find the angle of deviation of the particle as it comes out of the magnetic field if the lateral width d of the region is slightly larger than mvqB.

- π4
- π3
- π2
- π

**Q.**Two equal and opposite charge (+q and -q) are situated at x distance from each other, the value of potential at very far point will depend upon?

**Q.**1.A cell of emf 4 V and internal resistance 1 ohm is connected to a d.c. source of 10 V through a resistor of 5 ohm. Calculate the terminal voltage across the cell during charging. 2.The potential difference across a cell is 1.8V when a current of 0.5 A is drawn from it. The p.d. falls to 1.6V when a current of 1.0A is drawn. Find the emf and the internal resistance of the cell. 3.A 9 V battery is connected in series with a resistor. The terminal voltage is found to be 8 V. Current through the circuit is measured as 5 A. What is the internal resistance of the battery ?

**Q.**A uniform magnetic field exists in space as b=4icap.the magnetic flux through an area s=(2icap+4jcap)is

**Q.**A dielectric slab of dielectric constant K is placed between the plates of parallel plate capacitor carrying charge q the induced charge q on the surface of slab is given by 1)q=q-q/k 2)q=-q+q/k 3)q=q(1/k+1) 4)q=-q(1+1/k)