Download App

Magnetic Field — Physics STD 12 Science — Question

Gujarat BoardEnglish MediumSTD 12 SciencePhysicsMagnetic Field2 Marks
Question
A rectangular coil of 100 turns has length 5cm and width 4cm. 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

Physics STD 12 Science question papers→Gujarat Board STD 12 Science question papers→Gujarat Board question paper generator→

Similar questions

Describe briefly, with the help of a diagram, the role of the two important processes involved in the formation of a p-n junction.
→
A point charge produces an electric field of magnitude 5.0 $\mathrm{NC}^{-1}$ at a distance of 40cm from it. What is the magnitude of the charge?
→
A Rowland ring of mean radius 15 cm has 3500 turns of wire wound on a ferromagnetic core of relative permeability 800. What is the magnetic field B in the core for a magnetising current of 1.2 A?
→
Several capacitors of capacitance $C$ are connected in infinite number as shown in the figure. Find the value of total capacitance between points $A$ and $B$.
→
Draw the figures of field lines of (a) a bar magnet, (b) a current carrying finite solenoid and (c) an electric dipole.
→
The instantaneous voltage from an ac source is given by $\text{E}=300\sin314\text{t};$ what is the rms voltage of the source.
→
Explain the particle nature of light.
###
Explain the characteristics of photon.
→
Write laws of reflection.
→
  1. Write the necessary conditions for the phenomenon of total internal reflection to occur.
  2. Write the relation between the refractive index and critical angle for a given pair of optical media.
→
Write the definition of wave front.
→