MCQ
Assertion : A capacitor blocks direct current in the steady state.

Reason : The capacitive reactance of the capacitor is inversely proportional to frequency $f$ of the source of $emf$.

  • If both Assertion and Reason are correct and the Reason is a correct explanation of the Assertion.
  • B
    If both Assertion and Reason are correct but Reason is not a correct explanation of the Assertion.
  • C
    If the Assertion is correct but Reason is incorrect.
  • D
    If both the Assertion and Reason are incorrect.

Answer

Correct option: A.
If both Assertion and Reason are correct and the Reason is a correct explanation of the Assertion.
a
Capacitive reactance $X_{C}=\frac{1}{2 \pi f C}$

Frequency of direct current is zero i.e. $f=0$ $\Longrightarrow X_{C}=\infty$

Thus resistance of capacitor for direct current is very large and so it do not allow the direct current to pass through it.

Hence, option $A$ is correct.

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

Similar questions

Let $f = 50\, Hz$, and $C = 100\, \mu\, F$ in an $AC$ circuit containing a capicator only. If the peak value of the current in the circuit is $1.57$ $A$ at $t = 0$. The expression for the instantaneous voltage across the capacitor will be
What percentage of original radioactive atoms is left after five half lives
The first member of the Paschen series in hydrogen spectrum is of wavelength 18,800 Å. The short wavelengths limit of Paschen series is
The electric field inside a spherical shell of uniform surface charge density is
Two point charges placed at a certain distance r in air exert a force F on each other. Then the distance r' at which these charges will exert the same force in a medium of dielectric constant k is given by
Refractive index for a material for infrared light is
From a carbon nanotube of $1 \,\mu m$ length and $1 \,nm$ radius. $10$ electrons have been removed. Assume the resulting positive charge to be distributed umforrnly over the surface of the tube. The energy of an electron moving in a stable circular orbit around the axis along the length of the tube is calculated by applying the Bohr model. Accordingly, the frequency of radiation required to excite an electron from its ground state to the next level is in the range of (charge of the electron, $e =1.60 \times 10^{-19} \,C$; mass of the electron, $m _{ e }=9.11 \times 10^{-31} \,kg$; Planck's constant, $h =6.63 \times 10^{-34} \,Js$; Permittivity of free space, $\left.\varepsilon_0=8.85 \times 10^{-12}\,F / m \right)$
In the given circuit, the voltage across load resistance $\left(R_L\right)$ is:
The material of wire of potentiometer is
The output of OR gate is 1