Download App

2. Electric potential and capacitance — Physics STD 12 Science — Question

CBSE BoardEnglish MediumSTD 12 SciencePhysics2. Electric potential and capacitance1 Mark
MCQ
A parallel plate capacitor has a capacity $C$. The separation between the plates is doubled and a dielectric medium is introduced between the plates. If the capacity now becomes $2C$, the dielectric constant of the medium is
  • A
    $2$
  • B
    $1$
  • ✓
    $4$
  • D
    $8$
✓

Answer

Correct option: C.
$4$
c
(c) ${C_1} = {\varepsilon _0}\frac{A}{{{d_1}}}$ and ${C_2} = K{\varepsilon _0}\frac{A}{{{d_2}}}$
 $\frac{{{C_1}}}{{{C_2}}} = \frac{1}{K} \times \frac{{{d_2}}}{{{d_1}}}$ $ = \frac{C}{{2C}} = \frac{1}{K} \times \frac{{2d}}{d}$

$K = 4$

Need a full question paper?

Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.

Start Generating Free

Explore more

More "M.C.Q (1 Marks)" from 2. Electric potential and capacitance→2. Electric potential and capacitance — all question types→Physics STD 12 Science question papers→CBSE Board STD 12 Science question papers→CBSE Board question paper generator→

Similar questions

Four condensers are joined as shown in the adjoining figure. The capacity of each is 8 μF. The equivalent capacity between the points A and B will be
→
A cell of negligible resistance and $e.m.f.$ $2$ $volts$ is connected to series combination of $2$, $3$ and $5\, ohm$. The potential difference in volts between the terminals of $3\, ohm$ resistance will be
→
Consider the circuit shown in the figure. The current $I_3$ is equal to

→
The wires $1$ and $2$
→
Figure $(a)$ below shows a Wheatstone bridge in which $\text{P, Q, R, S}$ are fixed resistances, $G$ is a galvanometer and $B$ is a battery. For this particular case the galvanometer shows zero deflection. Now, only the positions of $B$ and $G$ are interchanged,. as shown in figure $(b).$ The new deflection of the galvanometer.
→
A beam of light of wavelength λ and with illumination L falls on a clean surface of sodium. If N photoelectrons are emitted each with kinetic energy E, then
→
A modulating signal $2 \sin \left(6.28 \times 10^{6}\right) t$ is added to the carrier signal $4 \sin \left(12.56 \times 10^{9}\right)$ t for amplitude modulation. The combined signal is passed through a non-linear square law device. The output is then passed through a band pass filter. The bandwidth of the output signal of band pass filter will be $MHz$.
→
A photon of energy 30 eV incident on the surface of a metal, due to which an electron with kinetic energy 27.5 eV is emitted. The work function of the metal surface will be :
→
Three capacitors of capacity $C_1,C_2,C_3$ are connected in series. Their total capacity will be
→
In the figure shown in $YDSE$, $a$ parallel beam of light is incident on the slit from $a$ medium of refractive index $n_1$. The wavelength of light in this medium is $\lambda_1$. $A$ transparent slab of thickness $‘t’$ and refractive index $n_3$ is put infront of one slit. The medium between the screen and the plane of the slits is $n_2.$ The phase difference between the light waves reaching point $‘O’$ (symmetrical, relative to the slits) is :
→