MHT CET · Physics · Alternating Current
A capacitor, an inductor and an electric bulb are connected in series to an a.c. supply of variable frequency. As the frequency of the supply is increased gradually, then the electric bulb is found to
- A increase in brightness.
- B decrease in brightness.
- C increase, reach a maximum and then decrease in brightness
- D show no change in brightness.
Answer & Solution
Correct Answer
(C) increase, reach a maximum and then decrease in brightness
Step-by-step Solution
Detailed explanation
The given circuit acts like a series LCR circuit
\(I=\frac{V}{Z}=\frac{V}{\sqrt{R_2+\left(\omega L-\frac{1}{\omega C}\right)^2}}\)
From the above formula, when \(\omega=0\), \(\mathrm{I}=\) maximum
When \(\omega\) is increased, I starts to decrease and when \(\omega=\frac{1}{\sqrt{\mathrm{LC}}}\) the current will be zero. This cycle will repeat going forward. So brightness will increase, reach a maximum and then decrease.
\(I=\frac{V}{Z}=\frac{V}{\sqrt{R_2+\left(\omega L-\frac{1}{\omega C}\right)^2}}\)
From the above formula, when \(\omega=0\), \(\mathrm{I}=\) maximum
When \(\omega\) is increased, I starts to decrease and when \(\omega=\frac{1}{\sqrt{\mathrm{LC}}}\) the current will be zero. This cycle will repeat going forward. So brightness will increase, reach a maximum and then decrease.
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 metal rod cools at the rate of \(4{ }^{\circ} \mathrm{C} / \mathrm{min}\) when its temperature is \(90^{\circ} \mathrm{C}\) and the rate of \(1{ }^{\circ} \mathrm{C} / \mathrm{min}\) when its temperature is \(30^{\circ} \mathrm{C}\). The temperature of the surrounding isMHT CET 2023 Medium
- A small ball of mass \(M\), radius \(R\) and density \(\rho\) moves with terminal velocity through a container filled with glycerine of density \(\sigma\). The viscous force acting on the ball is ( \(g=\) gravitational acceleration)MHT CET 2022 Medium
- The instrument which works on the principle of mutual inductance isMHT CET 2012 Easy
- For emission of light, a light emitting diode (LED) isMHT CET 2023 Easy
- Two circular loops P and Q of radii ' r 'and ' nr ' are made respectively from a uniform wire. Moment of inertia of loop Q about its axis is four times that of loop P about its axis. The value of ' \(n\) ' isMHT CET 2024 Medium
- The angular speed of the minute hand of a clock in degrees per second isMHT CET 2020 Easy
More PYQs from MHT CET
- When a capacitor is connected in series LR circuit, the alternating current flowing in the circuitMHT CET 2024 Easy
- What is the order of ease of dehydrohalogenation of alkyl halides?MHT CET 2024 Medium
- An inextensible string of length ' \(\ell\) ' fixed at one end, carries a mass ' m ' at the other end. If the string makes \(\frac{1}{\pi}\) revolutions per second around the vertical axis through the fixed end, the tension in the string is [The string makes an angle \(\theta\) with the vertical]MHT CET 2025 Medium
- A transformer having efficiency \(90 \%\) is working on 200 V and 3 kw power supply. If the current in the secondary coil is 6 A , the voltage across the secondary coil and the current in the primary coil are respectivelyMHT CET 2024 Easy
- Which one of the following is NOT a bacterial herbicide?MHT CET 2017 Medium
- The current in resistor in the following circuit is
MHT CET 2019 Medium