Download App

Gausss Law — Physics STD 12 Science — Question

Gujarat BoardEnglish MediumSTD 12 SciencePhysicsGausss Law1 Mark
MCQ
A closed surface S is constructed around a conducting wire connected to a battery and a switch (figure). As the switch is closed, the free electrons in the wire start moving along the wire. In any time interval, the number of electrons entering the closed surface S is equal to the number of electrons leaving it. On closing the switch, the flux of the electric field through the closed surface:
  • A
    Is increased.
  • B
    Is decreased.
  • ✓
    Remains unchanged.
  • D
    Remains zero.
✓

Answer

Correct option: C.
Remains unchanged.
Explanation:

The flux of the electric field through the closed surface is remain unchanged.
Because the no. of electric field lines enter in the closed path = no. of electric field lines existsin the closed path.

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

Physics STD 12 Science question papers→Gujarat Board STD 12 Science question papers→Gujarat Board question paper generator→

Similar questions

A positively charged ring is in $y-z$ plane with its centre at origin. A positive test charge $q_0$, held at origin is released along $x$-axis, then its speed
→
A magnet can only repel another magnet. So, $‘X\ ’$ is a surer test of magnetism. Identify $X.$
→
10 wires (same length, same area, same material) are connected in parallel and each has 1 Ω resistance, then the equivalent resistance will be
→
Two identical cells, when connected either in parallel or in series gives same current in an external resistance $5\,\Omega$. The internal resistance of each cell will be $.............\,\Omega$.
→
If $1 g$ hydrogen is converted into $0.993 \,gm$ of helium in a thermonuclear reaction, the energy released in the reaction is ......... $J$
→
Two point charges $( + Q)$ and $( - 2Q)$ are fixed on the $X-$axis at positions $a$ and $2a$ from origin respectively. At what positions on the axis, the resultant electric field is zero
→
Water of volume $2$ litre in a container is heated with a coil of $1 \ kW$ at $27^{\circ} \mathrm{C}$. The lid of the container is open and energy dissipates at rate of $160 \mathrm{~J} / \mathrm{s}$. In how much time temperature will rise from $27^{\circ} \mathrm{C}$ to $77^{\circ} \mathrm{C}$ [Given specific heat of water is $4.2 \mathrm{~kJ} / \mathrm{kg} ]$
 
→
Figure shows a cubical room $ABCD$ with the wall $CD$ as a plane mirror. Each side of the room is $3\,m$. We place a camera at the midpoint of the wall $AB$. At what distance should the camera be focussed to photograph an object placed at $A$
→
Light of frequency $4 n_0$ is incident on the metal of the threshold frequency $\mathrm{n}_0$. The maximum kinetic energy of the emitted photoelectrons is
→
A $10\, ohm$ electric heater operates on a $110\, V$ line. Calculate the rate at which it develops heat in ............... $watts$
→