NEET Physics - New - Electrostatic Potential and Capacitance

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Question - 1

In a certain region of space with volume 0.2 m3, the electric potential is found to be 5 V throughout. The magnitude of electric field in this region is _______.

  • A 5 N/C
  • B Zero
  • C 0.5 N/C
  • D 1 N/C

Question - 2

The capacitance of a parallel plate capacitor with air as medium is 6 mf. With the introduction of a dielectric medium, the capacitance becomes 30 mF. The permittivity of the medium is
\(\left(\Sigma_{0}=8.85 \times 10^{-12} \mathrm{C}^{2} \mathrm{~N}^{-1} \mathrm{~m}^{-2}\right)\)

  • A 5.00C2N-1m-2
  • B 0.44 x l0-13C2N-lm-2
  • C 1.77 x l0-12C2N-1m-2
  • D 0.44 x 10-10C2N-1m-2

Question - 3

A hollow metal sphere of radius R is uniformly charged. The electric field due to the sphere at a distance r from the centre ______.

  • A Zero as r increases for r < R, decreases as r increases for r>R
  • B Zero as r increases for r < R, increases as r increases for r> R
  • C Decreases as r increases for r < R and for r > R
  • D Increases as r increases for r < R and for r > R

Question - 4

A parallel plate capacitor of capacitance 20 mF is being charged by a voltage source whose potential is changing at the rate of 3 V/s. The conduction current through the connecting wires, and the displacement current through the plates of the capacitor, would be, respectively.

  • A 60 mA, 60 mA
  • B 60 mA, zero
  • C Zero, zero
  • D Zero,60 mA

Question - 5

A parallel plate air capacitor of capacitance C is connected to a cell of emf Zand then disconnected from it.A dielectric slab of dielectric constant K, which can just fill the air gap of the capacitor, is now inserted in it. Which of the following is incorrect.

  • A The energy stored in the capacitor decreases K times.
  • B The chance in energy stored is \(\frac{1}{2} C V^{2}\left(\frac{1}{K}-1\right)\)
  • C The charge on the capacitor is not conserved.
  • D The potential difference between the plates decreases K times.

Question - 6

In a region, the potential is represented by V(x, y, z') = 6x - 8xy - 8y + 6yz, where V is in volts and x, y, z are in metres. The electric force experienced by a charge of 2 coulomb situated at point (1, 1, 1) is ________.

  • A 6\(\sqrt{5}\)N
  • B 30 N
  • C 24 N
  • D 4\(\sqrt{35}\)N

Question - 7

A conducting sphere of radius R is given a charge Q. The electric potential and the electric field at the centre of the sphere respectively are _______.

  • A \(\text { Zero and } \frac{Q}{4 \pi \varepsilon_{0} R^{2}}\)
  • B \(\frac{Q}{4 \pi \varepsilon_{0} R} \text { and Zero }\)
  • C \(\frac{Q}{4 \pi \varepsilon_{0} R} \text { and } \frac{Q}{4 \pi \varepsilon_{0} R^{2}}\)
  • D Both are zero

Question - 8

Two thin dielectric slabs of dielectric constants K1 and K2(K1 < K2) are inserted between plates of a parallel plate capacitor, as shown in the figure. The variation of electric field 'E' between the plates with distance 'd' as measured from plate P is correctly shown by:

  • A
  • B
  • C
  • D

Question - 9

A, B and C are three points in a uniform electric field. The electric potential is

 

  • A  maximum at B
  • B maximum at C
  • C same at all the three points A, B and C
  • D maximum at A

Question - 10

A parallel plate capacitor has a uniform electric field E in the space between the plates. If the distance between the plates is d and area of each plate is A, the energy stored in the capacitor is __________.

  • A \(\frac{1}{2} \varepsilon_{0} E^{2}\)
  • B \(\mathrm{E}^{2} \mathrm{Ad} / \varepsilon_{0}\)
  • C \(\frac{1}{2} \varepsilon_{0} E^{2} Ad\)
  • D \(\varepsilon_{0} \text { EAd }\)