A magnet of length 10 cm and pole strength 4 - 10-4 A-m is placed in a magnetic field of induction 2- 10-5 Wb- m-2- such that the axis of the magnet makes an angle 30o with the lines of induction- The moment of the couple acting on the magnet is

A bar magnet of length $10 c m$ and pole strength $2 A m$ makes an angle $60^{o}$ with a uniform magnetic field of induction $50 T$ . The couple acting on it :

Q. A bar magnet when placed at an angle of

30^{o}

to the direction of magnetic field of induction of

5 \times 10^{- 5} T

, experiences a moment of a couple

2.5 \times 10^{- 6} N - m

. If the length of the magnet is

5 c m

its pole strength is:

Q. If a magnet of length

10 c m

and pole strength

40 A - m

is placed at an angle of

45

in a uniform induction field of intensity

2 \times 10^{- 4} T

. The couple acting on it is

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A magnet of length 10 cm and pole strength 4×10−4 A.m is placed in a magnetic field of induction 2×10−5 Wb−m−2, such that the axis of the magnet makes an angle 30o with the lines of induction. The moment of the couple acting on the magnet is

The correct option is B 4×10−10 Nml=10 cmP=4×154AmB=2×10−5Tθ=30om=plz=→m×→B=mPsinθ=4×10−4×10−5=4×10−10 Nm

A magnet of length $10 c m$ and pole strength $4 \times 10^{- 4} A . m$ is placed in a magnetic field of induction $2 \times 10^{- 5} W b - m^{- 2}$ , such that the axis of the magnet makes an angle $30^{o}$ with the lines of induction. The moment of the couple acting on the magnet is

The correct option is B $4 \times 10^{- 10} N m$
$l = 10 c m$
$P = 4 \times 15^{4} A m$
$B = 2 \times 10^{- 5} T$
$θ = 30^{o}$
$m = p l$
$z = \to m \times \to B$
$= m P sin θ$
$= 4 \times 10^{- 4} \times 10^{- 5}$
$= 4 \times 10^{- 10} N m$