Download App

6. Electromagnetic induction — Physics STD 12 Science — Question

CBSE BoardEnglish MediumSTD 12 SciencePhysics6. Electromagnetic induction1 Mark
MCQ
For $L-R$ circuit, the time constant is equal to
  • ✓
    twice the ratio of the energy stored in the magnetic field to the rate of dissipation of energy in the resistance
  • B
    ratio of the energy stored in the magnetic field to the rate of dissipation of energy in the resistance
  • C
    half the ratio of the energy stored in the magnetic field to the rate of dissipation of energy in the resistance
  • D
    square of the ratio of the energy stored in the magnetic field to the rate of dissipation of energy in the resistance
✓

Answer

Correct option: A.
twice the ratio of the energy stored in the magnetic field to the rate of dissipation of energy in the resistance
a
The time required for the current flowing in the $LR$ series circuit to reach its maximum steady state value is equivalent to about $5$ time constants or $5 \tau$. This time constant $\tau$, is measured by $\tau=L / R$, in seconds, where $R$ is the value of the resistor in ohms and $L$ is the value of the inductor in Henries

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 "M.C.Q (1 Marks)" from 6. Electromagnetic induction→6. Electromagnetic induction — all question types→Physics STD 12 Science question papers→CBSE Board STD 12 Science question papers→CBSE Board question paper generator→

Similar questions

$A$ thin wire of length $2m$ is perpendicular to the $xy$ plane. It is moved with velocity $\vec v = (2\hat i + 3\hat j + \hat k)\,m/s$ through $a$ region of magnetic induction $\vec B = (\hat i + 2\hat j)\,\,Wb/{m^2}$. Then potential difference induced between the ends of the wire :........$volts$
→
Given below are symbols for some logic gates

The XOR gate and NOR gate respectively are
→
A cell of $e.m.f.$ $1.5\,V$ having a finite internal resistance is connected to a load resistance of $2\,\Omega $. For maximum power transfer the internal resistance of the cell should be ............. $ohm$
→
The energy equivalent of 1 kilogram of matter is about
→
If $\varepsilon_0$ and $\mu_0$ are respectively, the electric permittivity and the magnetic permeability of free space, $\varepsilon$ and $\mu$ the corresponding quantities in a medium, the refractive index of the medium is
→
The area of its cross-section is $1.2 \times {10^{ - 3}}{m^2}$. Around its central section, a coil of $300$ turns is wound. If an initial current of $2A$ in the solenoid is reversed in $0.25\, sec$, then the $e.m.f$. induced in the coil is
→
Magnetic moment of a small bar magnet is $1.2 A- m ^2$. Magnetisation field at a distance of 0.1 m on its axis is :
→
Two infinite plane parallel sheets separated by a distance $d$ have equal and opposite uniform charge densities $\sigma $. Electric field at a point between the sheets is
→
Age of a tree is determined using radio-isotope of
→
A star producing light of wavelength $6000 Å$ moves away from the earth with a speed of $5\, km/sec$. Due to Doppler effect the shift in wavelength will be......$\mathop A\limits^o $ $(c = 3 \times {10^8}m/\sec )$
→