Download App

Moving Charges and Magnetism — Physics STD 12 Science — Question

Rajasthan BoardEnglish MediumSTD 12 SciencePhysicsMoving Charges and Magnetism2 Marks
Question
A rectangular coil of $100$ turns has length $5\ cm$ and width $4\ cm.$ It is placed with its plane parallel to a uniform magnetic field and a current of $2A$ is sent through the coil. Find the magnitude of the magnetic field $B$ if the torque acting on the coil is $0.2N m^{-1}$.
✓

Answer

$\tau=\text{ni}\overrightarrow{\text{A}}\times\overrightarrow{\text{B}}$
$\Rightarrow\tau=\text{ni}\text{ AB}\sin90^\circ$
$\Rightarrow0.2=100\times2\times5\times4\times10^{-4}\times\text{B}$
$\Rightarrow\text{B}=\frac{0.2}{100\times2\times5\times4\times10^{-4}}=0.5$ Tesla

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 "2 Marks Questions" from Moving Charges and Magnetism→Moving Charges and Magnetism — all question types→Physics STD 12 Science question papers→Rajasthan Board STD 12 Science question papers→Rajasthan Board question paper generator→

Similar questions

Find the loss in the mass of $1$ mole of an ideal monatomic gas kept in a rigid container as it cools down by $10^\circ C.$ The gas constant $R = 8.3\ J/mol-K.$
→
Show that the internal energy of the air (treated as an ideal gas) contained in a room remains constant as the temperature changes between day and night. Assume that the atmospheric pressure around remains constant and the air in the room maintains this pressure by communicating with the surrounding through the windows, doors, etc.
→
In RL and RC series AC circuits the resonance phenomenon isn't possible. Why?
→
The voice of a person, who has inhaled helium, has a remarkably high pitch. Explain on the basis of resonant vibration of vocal cord filled with air and with helium.
→
Monochromatic light entering from one medium to another, its wavelength changes but the frequency does not change, explain.
→
A sample of $0.177g$ of an ideal gas occupies $1000\ cm^3$ at $\text{STP}.$ Calculate the $\text{rms}$ speed of the gas molecules.
→
Find the equivalent capacitance of the syatem shown in figure between the points $a$ and $b.$
→
Area of cross-section of a wire is $1.0 \times 10^{-7} m^2$ and the number of free electrons per cubic metre in the wire is $2 \times 10^{28}$ per $m ^3$. A current of 3.2 A is flowing in the wire. Find (i) current density in the wire (ii) drift velocity of free electrons.
→
Derive the equation of magnetic potential energy of a magnetic dipole placed in a uniform magnetic field and discuss its special cases.
→
A nucleus  $\frac{23}{10}$ Ne undergoes β− decay and becomes $\frac{23}{11}$Na. Calculate the maximum kinetic energy of electrons emitted assuming that the daughter nucleus and anti-neutrino carry negligible kinetic energy.$\left\{\text{mass of} \frac{23}{10} Ne = 22.994466 u\right\}$
$\left\{\text{mass of}\frac{23}{11}Na=22.989770u\right\}$
$\left\{ 1u = 931.5\text{MeV}/ c^{2}\right\}$
→