A magnet of moment 1-2 Am2 is kept suspended in a magnetic field of induction 2- 10-6- The work done in rotating it through 120 o is-

The correct option is A 3.6× 10^ 6J m=1.2Am^2 B=2× 10^ 6T θ =120^o U= mBcos 0^o U_1= mB = 2.4× 10^ 6J U_2= mBcos 120^o ...

290

You visited us 290 times! Enjoying our articles? Unlock Full Access!

Byju's Answer

Standard XII

Physics

More about Magnetic Dipoles

A magnet of m...

Question

A magnet of moment $1.2 A m^{2}$ is kept suspended in a magnetic field of induction $2 \times 10^{- 6}$ . The work done in rotating it through 120 $^{o}$ is:

2.4 \times 10^{- 6} J

No worries! We‘ve got your back. Try BYJU‘S free classes today!

4.8 \times 10^{- 6} J

No worries! We‘ve got your back. Try BYJU‘S free classes today!

1.2 \times 10^{- 6} J

No worries! We‘ve got your back. Try BYJU‘S free classes today!

3.6 \times 10^{- 6} J

Right on! Give the BNAT exam to get a 100% scholarship for BYJUS courses

Open in App

Solution

The correct option is A $3.6 \times 10^{- 6} J$
$m = 1.2 A m^{2}$
$B = 2 \times 10^{- 6} T$
$θ = 120^{o}$
$U = - m B cos 0^{o}$
$U_{1} = - m B$
$= - 2.4 \times 10^{- 6} J$
$U_{2} = - m B cos 120^{o}$
$= \frac{m B}{2}$
$= 1.2 \times 10^{- 6} J$
$w = U_{2} - U_{1}$
$= 1.2 \times 10^{- 6} + 2.4 \times 10^{- 6}$
$= 3.6 \times 10^{- 6}$

Suggest Corrections

Similar questions

A magnet of moment 4Am $^{2}$ is kept suspended in a magnetic field of induction $5 \times 10^{- 5} T$ . The workdone in rotating it through 180 $^{0}$ is

Work done in splitting a drop of water of 1 mm radius into $10^{6}$ droplets is (Surface tension of water = $72 \times 10^{- 3} J / m^{2})$

Q. A bar magnet of magnetic moment 6 J/T is aligned at

60^{0}

with a uniform external magnetic field of 0.44 T. Calculate (a) the work done in turning the magnet to align its magnetic moment (i) normal to the magnetic field, (ii) opposite to the magnetic field, and
(b) the torque on the magnet in the final orientation
in case (ii).

Q. Magnetic field

\to B = 3 x^i

exists in space. Energy stored in a cylinderical region of length 1m along x-axis with one end at origin is [Radius of the cylinder is 2m]

Q. A freezer has coefficient of performance

5

. When

3.6 \times 10^{6} J

work is done on the freezer, what mass of water at

0^{0} C

is converted to ice cubes at

0^{0} C

Join BYJU'S Learning Program

A magnet of moment 1.2 Am2 is kept suspended in a magnetic field of induction 2×10−6. The work done in rotating it through 120o is:

The correct option is A 3.6×10−6Jm=1.2Am2B=2×10−6Tθ=120oU=−mBcos0oU1=−mB=−2.4×10−6JU2=−mBcos120o=mB2=1.2×10−6Jw=U2−U1=1.2×10−6+2.4×10−6=3.6×10−6

A magnet of moment $1.2 A m^{2}$ is kept suspended in a magnetic field of induction $2 \times 10^{- 6}$ . The work done in rotating it through 120 $^{o}$ is: