Related InterviewSolutions

• An electrical technician requires a capacitance of `2 muF` in a circuit across a potential difference of 1 kV. A large number of `1 mu F` capacitors are available to him each of which can withstand a potential difference of not more than 400 V. Suggest a possible arrangement that requires the minimum number of capacitors.
• The capacitance of a parallel plate capacitor with air as medium is `3 muF.` with the introduction of a dielectric medium between the plates, the capacitance becomes `15mu F.` The permittivity of the medium isA. `5C^(2)N^(-1)M^(-2)`B. `15C^(2)N^(-1)m^(-2)`C. `0.44xx10^(-10)C^(2)N^(-1)m^(2)`D. `8.854xx10^(-11)C^(2)N^(-1)m^(-2)`
• Assertion. Dielectric polarization means formation of positive and negative charges inside the dielectric. Reason. Free electrons are formed in this process.A. If both assertion and reason are ture and reason is the correct explanation of assertion.B. If both assertin and reason are ture but reason is not the correct explanation of assertion .C. If assertion is true but reason is false.D. If both assertion and reason are false.
• A molecule of a substance has a permanent electric dipole moment of magnitude `10^(-29) `C m. A mole of this substance is polarized at low temperature by appling a strong elecrostatic field of magnitude `10^(6) V m^(-1)`. The direction of the field is suddenly changed by an angle of `60^(@)`. Estimate the heat released by the substance in aligning its dipole along the new direction of the field. For simplicity, assume `100%` polarisation of sample.
• Electric field inside a conductor can be zero only, if potential inside the onductor isA. If both assertion and reason are ture and reason is the correct explanation of assertion.B. If both assertin and reason are ture but reason is not the correct explanation of assertion .C. If assertion is true but reason is false.D. If both assertion and reason are false.
• Three concentric spherical shells have radii `a, b` and `c(a lt b lt c)` and have surface charge densities `sigma, -sigam` and `sigma` respectively. If `V_(A), V_(B)` and `V_(C)` denote the potentials of the three shells, then for `c = q + b`, we haveA. `V_(C)=V_(B)=V_(A)`B. `V_(C)=V_(A)ne V_(B)`C. `V_(C)= V_(B)ne V_(A)`D. `V_(C) ne V_(B) ne V_(A)`
• The magnitude of electric field `vecE` in the annular region of a charged cylindrical capacitor.A. is the same throughoutB. is higher near the outer cylinder than near the inner cylinderC. varies as `(1)/(r^(2))` where r is the distance from the axisD. varies as `(1)/(r^(3))` where r is the distance from the axis.
• Which of the following statements is/are true about the principle of Van de Graaff generator ?A. The actiion of sharp points.B. The charge given to a hollow conductor is transferrec to outer surface and it distibuted uniformly over it.C. It is used for accelerating uncharged particle.D. Both (a) and (b) are true.
• Two spheres of radius `a` and `b` respectively are charged and joined by a wire. The ratio of electric field of the spheres isA. `a/b`B. `b/a`C. `(a^(2))/(b^(2))`D. `(b^(2))/(a^(2))`
• A parallel plate condenser is charged by connected it to a battery. The battery is disconnected and a glass slab is introduced between the plates. ThenA. Charge and potential difference.B. Potential difference and energy stored.C. Energy stored and capacitance.D. Capacitance and charge.