JEE Mains · Physics · STD 12 -7. Alternating current
The current flowing through an ac circuit is given by \(I=5 \sin (120 \pi t) A\) How long will the current take to reach the peak value starting from zero?
- A \(\frac{1}{60} \; s\)
- B \(60 \; s\)
- C \(\frac{1}{120} \; s\)
- D \(\frac{1}{240} \; s\)
Answer & Solution
Correct Answer
(D) \(\frac{1}{240} \; s\)
Step-by-step Solution
Detailed explanation
\(\omega=120 \pi=\frac{2 \pi}{T} \Rightarrow T=\frac{1}{60} sec\) time taken to reach peak value \(=\frac{T}{4}=\frac{1}{240} s\)
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
- Two radioactive substances A and B of mass numbers \(200\) and \(212\) respectively, shows spontaneous \(\alpha\)-decay with same \(Q\) value of \(1\) MeV. The ratio of energies of \(\alpha\)-rays produced by A and B is ________.JEE Mains 2026 Medium
- For the \(LCR\) circuit, shown here, the current is observed to lead the applied voltage. An additional capacitor \(C '\) , when joined with the capacitor \(C\) present in the circuit , makes the power factor of the circuit unity. The capacitor \(C'\), must have been connected in
JEE Mains 2015 Hard - A point charge \(2 \times 10^{-2}\,C\) is moved from \(P\) to \(S\) in a uniform electric field of \(30\,NC ^{-1}\) directed along positive \(x\)-axis. If coordinates of \(P\) and \(S\) are \((1,2\), \(0) m\) and \((0,0,0) m\) respectively, the work done by electric field will be \(.........\,mJ\)JEE Mains 2023 Medium
- A ceiling fan having 3 blades of length \(80 \mathrm{~cm}\) each is rotating with an angular velocity of \(1200\ \mathrm{rpm}\). The magnetic field of earth in that region is \(0.5 \ \mathrm{G}\) and angle of dip is \(30^{\circ}\). The emf induced across the blades is \(N \pi \times 10^{-5} \mathrm{~V}\). The value of \(\mathrm{N}\) is _______.JEE Mains 2024 Hard
- Suppose there is a uniform circular disc of mass M kg and radius r m shown in figure. The shaded regions are cut out from the disc. The moment of inertia of the remainder about the axis A of the disc is given by \(\frac{ x }{256} Mr ^2\). The value of x is ___________.
JEE Mains 2026 Easy - A liquid drop of diameter \(2\) mm breaks into \(512\) droplets. The change in surface energy is \(\alpha \times 10^{-6}\) J. The value of \(\alpha\) is _______. (Take surface tension of liquid \(= 0.08\) N/m)JEE Mains 2026 Medium
More PYQs from JEE Mains
- The value of \(\frac{1}{1 ! 50 !}+\frac{1}{3 ! 48 !}+\frac{1}{5 ! 46 !}+\ldots .+\frac{1}{49 ! 2 !}+\frac{1}{51 ! 1 !}\) is \(.............\).JEE Mains 2023 Hard
- A steel wire having a radius of \(2.0\, mm\), carrying a load of \(4\, kg\), is hanging from a ceiling. Given that \(g = 3.1\pi \,m{s^{ - 2}}\) , what will be the tensile stress that would be developed in the wire?JEE Mains 2019 Medium
- The shortest distance between the line \(\frac{x-3}{4}=\frac{y+7}{-11}=\frac{z-1}{5} \text { and } \frac{x-5}{3}=\frac{y-9}{-6}=\frac{z+2}{1}\) is :JEE Mains 2024 Medium
- A block of metal weighing \(2 \,kg\) is resting on a frictionless plane (as shown in figure). It is struck by a jet releasing water at a rate of \(1 \,kgs ^{-1}\) and at a speed of \(10 \,ms ^{-1}\). Then, the initial acceleration of the block, in \(ms ^{-2}\), will be .................
JEE Mains 2022 Medium - The plane which bisects the line segment joining the points \((-3, -3, 4)\) and \((3, 7, 6)\) at right angles, passes through which one of the following points?JEE Mains 2019 Hard
- A circular loop of radius \(20\text{ cm}\) and resistance \(2\ \Omega\) is placed in a time varying magnetic field \(\vec{B} = (2t^2 + 2t + 3)\text{ T}\). At \(t = 0\), for the plane of the loop being perpendicular to the magnetic field and, the induced current in the loop at \(t = 3\text{ s}\) is \(\dfrac{\alpha}{50}\text{ A}\). The value of \(\alpha\) is _______.
(Take \(\pi = 22/7\))JEE Mains 2026 Medium