MHT CET · Physics · Alternating Current
In series LCR circuit, 'R' represents resistance of electric bulb. If the frequency of a.c. supply is doubled, the value of inductance ' L ' and capacitance ' C ' should be
- A both doubled.
- B made four times.
- C made eight times.
- D both halved simultaneously.
Answer & Solution
Correct Answer
(D) both halved simultaneously.
Step-by-step Solution
Detailed explanation
In an LCR circuit
\(\begin{aligned}
I=\frac{E}{Z} & =\frac{E}{\sqrt{R^2+\left(X_L-X_C\right)^2}} \\
& =\frac{E}{\sqrt{R^2+\left(2 \pi f L-\frac{1}{2 \pi f C}\right)^2}}
\end{aligned}\)
To keep I constant, if f is doubled both L and C should be halved.
\(\begin{aligned}
I=\frac{E}{Z} & =\frac{E}{\sqrt{R^2+\left(X_L-X_C\right)^2}} \\
& =\frac{E}{\sqrt{R^2+\left(2 \pi f L-\frac{1}{2 \pi f C}\right)^2}}
\end{aligned}\)
To keep I constant, if f is doubled both L and C should be halved.
See the Complete Solution
Get step-by-step explanations for this and 2.5 Lakh+ more JEE, NEET & CET questions.
- Unlock all solutions
- Practice the full chapter
- Track accuracy across PYQs
4.8 rated on Google Play · 14,000+ reviews
More questions from Physics
- A body weights 500 Non the surface of earth. At what distance below the surface of earth it weight \(250 \mathrm{~N}\) ?
(Radius of earth, \(R=6400 \mathrm{~km}\) )MHT CET 2022 Medium - Two coils \(P\) and \(Q\) each of radius \(R\) carry currents I and \(\sqrt{8} \mathrm{I}\) respectively in same direction. Those coils are lying in perpendicular planes such that they have a common centre. The magnitude of the magnetic field at the common centre of the two coils is ( \(\mu_0=\) permeability of free space)MHT CET 2024 Medium
- The material used for solar cell should have band gapMHT CET 2025 Easy
- A square lamina of side ' \(b\) ' has same mass as a disc of radius ' \(R\) ' the moment of inertia of the two objects about an axis perpendicular to the plane and passing through the centre is equal. The ratio \(\frac{\mathrm{b}}{\mathrm{R}}\) isMHT CET 2023 Medium
- For a common emitter transistor, if \(\frac{\mathrm{I}_{\mathrm{C}}}{\mathrm{I}_{\mathrm{E}}}=0.95\), then the current gain isMHT CET 2025 Easy
- An air-filled parallel plate capacitor has a capacity \(2 \mathrm{pF}\), The separation of the plates is doubled and the interspace between the plates is filled with dielectric material, then the capacity is increased to \(6 \mathrm{pF}\), The dielectric constant of the material isMHT CET 2021 Medium
More PYQs from MHT CET
- The area (in sq. units) of the region bounded by the curve \(x^2=4 y\) and the straight line \(x=4 y-2\) isMHT CET 2024 Easy
- Which from following polymers is grouped in the category of elastomers?MHT CET 2023 Easy
- The distance ' \(\mathrm{s}\) ' in meters covered by a particle in \(\mathrm{t}\) seconds is given by \(s=2+27 t-t^3\). The particle will stop after
distance.MHT CET 2021 Easy - Propene when treated with cold conc. forms a compound which on heating with water givesMHT CET 2019 Medium
- The pressure inside a soap bubble A is 1.01 atmosphere and that in a soap bubble B is 1.02 atmosphere. The ratio of volume of bubble A to that of \(B\) is [Surrounding pressure \(=1\) atmosphere \(]\)MHT CET 2024 Medium
- If \(\mathrm{y}+\frac{\mathrm{d}}{\mathrm{d} x}(x \mathrm{y})=x(\sin x+\log x)\) thenMHT CET 2025 Medium