Download App

Capacitors — Physics STD 12 Science — Question

Rajasthan BoardEnglish MediumSTD 12 SciencePhysicsCapacitors1 Mark
Question
When a dielectric slab is gradually inserted between the plates of an isolated parallel-plate capacitor, the energy of the system decreases. What can you conclude about the force on the slab exerted by the electric field?
✓

Answer

As the energy of the system decreases, the change in the energy is negative.
Force is defined as a negative rate of change of energy with respect to distance.
$\text{F}=-\frac{\delta\text{U}}{\delta\text{x}}$
So, as the energy decreases, the force due to the electric field of the capacitor increases when the dielectric is dragged into the capacitor.

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 "1 Marks Question" from Capacitors→Capacitors — all question types→Physics STD 12 Science question papers→Rajasthan Board STD 12 Science question papers→Rajasthan Board question paper generator→

Similar questions

Write the expression for speed of electromagnetic waves in a medium of electrical permittivity $\epsilon$ and magnetic permeability $\mu$.
→
"Magnetic field lines form closed curves." Why?
→
Name the part of electromagnetic spectrum which is used for taking photographs of earth under foggy conditions from great heights.
→
You are given following three lenses. Which two lenses will you use as an eyepiece and as an objective to construct an astronomical telescope?
Lenses Power $(P)$ Aperture $(A)$
$L_1$ $3 D $ $8 \ cm$
$L_2$ $6 D$ $1 \ cm$
$L_3$ $10 D$ $1 \ cm$
→
Four $2\ cm \times 2\ cm \times 2\ cm$ cubes of ice are taken out from a refrigerator and are put in $200\ ml$ of a drink at $10^\circ C.$
  1. Find the temperature of the drink when thermal equilibrium is attained in it.
  2. If the ice cubes do not melt completely, find the amount melted. Assume that no heat is lost to the outside of the drink and that the container has negligible heat capacity. Density of ice $= 900\ kg-m^{-3}$, density of the drink $= 1000\ kg-m^{-3}$, specific heat capacity of the drink $= 4200Jkg^{-1}-K^{-1}$, latent heat of fusion of ice $= 3.4 \times 10^5J-kg^{-1}.$
→
How does conductance of a semi-conductor changes with increase in temperature?
→
A cubical box is to be constructed with iron sheets $1\ mm$ in thickness. What can be the minimum value of the external edge so that the cube does not sink in water? Density of iron $= 8000\ kg/m^3$ and density of water $= 1000\ kg/m^3.$
→
Can a hot$-$wire ammeter be used to measure a direct current having a constant value? Do we have to change the graduations?
→
The capacitance of a charged capacitor is C and the energy stored in it is U. What is the value of charge on the capacitor?
→
Two proton beams going in the same direction repel each other whereas two wires carrying currents in the same direction attract each other. Explain.
→