Download App

AC Circuits — Physics STD 12 Science — Question

Maharashtra BoardEnglish MediumSTD 12 SciencePhysicsAC Circuits3 Marks
Question
An alternating emf is given by $e=220 \sin 314.2 t$ (in volt). Find its
(i) peak value
(ii) rms value
(iii) average value over half cycle
(iv) frequency
(iv) period
(vi) value at $\frac{T}{4}$.
✓

Answer

Data: $e =220 \sin 314.2 t (\text { in volt })_{ t } t =\frac{T}{4}$
(i) Comparing the given equation with $e=e_0 \sin \omega t$, we get, peak value, $e_0=220 V$.
(ii) $e_{ rms }= e _{ o } / \sqrt{2}=155.6 V$
(iii) $e _{ av }$ (over half cycle) $=\frac{2}{\pi} e _0=\frac{2(220)}{3.142}=140 V$
(iv) $\omega=2 \pi f=314.2 \therefore$ The frequency,
$
f =\frac{\omega}{2 \pi}=\frac{314.2}{2(3.142)}=50 Hz
$
(v) The period, $T==\frac{1}{f}=\frac{1}{50}=0.02$ same
(vi) $e=220 \sin \left(\frac{2 \pi}{T} \cdot \frac{T}{4}\right)=220 \sin \frac{\pi}{2}=220 v$

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

Explore more

More "Answer the following in Brief" from AC Circuits→AC Circuits — all question types→Physics STD 12 Science question papers→Maharashtra Board STD 12 Science question papers→Maharashtra Board question paper generator→

Similar questions

A cyclotron is used to accelerate protons to a kinetic energy of \(5 MeV\). If the strength of magnetic field in the cyclotron is \(2 T\), find the radius and the frequency needed for the applied alternating voltage of the cyclotron. (Given: Velocity of proton \(=3 \times 10^7 m / s\) )
→
State Stoke’s law and give two factors affecting angle of contact.
→
A plane wavefront of light of wavelength $5000 A$ is incident on two slits in a screen perpendicular to the direction of light rays. If the total separation of 10 bright fringes on a screen $2 m$ away is $4 mm$, find the distance between the slits.
→
The equation of simple harmonic progressive wave is given by \(Y =0.05 \sin \pi\left[20 t-\frac{x}{6}\right]\), where all quantities are in S.I. units, Calculate the displacement of a particle at \(5 m\) from origin and at the instant 0.1 second.
→
A moving coil galvanometer has a resistance of \(25 \Omega\) and gives a full scale deflection for a current of \(10 mA\). How will you convert it into a voltmeter having range \(0-100 V\) ?
→
A particle carrying $5$ electrons starts from rest and is accelerated through a potential difference of $8900 V$. Calculate the $KE$ acquired by it in $MeV. [$Charge on electron $=1.6 \times 10^{-} \left.{ }^{19} C \right]$
→
Define (1) cohesive force (2) adhesive force.
Give one example in each case.
→
Determine the change in wavelength of light during its passage from air to glass, if the refractive index of glass with respect to air is 1.5 and frequency of light is \(4 \times 10^{14} Hz\). ( c\(\left.=3 \times 10^8 m / s \right)\)
→
Define and explain surface energy of a liquid.
OR
Define surface energy.
OR
State its dimensions and SI unit.
OR
Why do molecules of a liquid in the surface film possess extra energy?
→
The refractive indices of water and diamond are \(\frac{4}{3}\) and 2.42 respectively. Find the speed of light in water and diamond. \(\left(c=3 \times 10^8 m / s \right)\)
→