A student says, "If a bar magnet is cut transversely, each piece becomes weaker because its pole strength decreases." Which evaluation is correct?
AThe statement is correct because both pole strength and dipole moment decrease
BThe statement is incorrect because pole strength remains the same, though dipole moment decreases
CThe statement is incorrect because both pole strength and dipole moment remain unchanged
DThe statement is correct because only pole strength decreases
Answer & Solution
Correct answer: B. The statement is incorrect because pole strength remains the same, though dipole moment decreases
The claim confuses pole strength with dipole moment. The notes clearly state that for a transverse cut, pole strength is unaffected, but dipole moment becomes half. So the magnet's moment decreases, not its pole strength.
Related questions
A storage battery of emf 8.0 V and internal resistance 0.5 $\Omega$ is charged by a 120 V The number density of free electrons in a copper wire is $8.5 \times 10^{28}\ \text{m}^{-3A heating element has resistance 100 $\Omega$ at 27.0 °C. Its temperature coefficient of rA wire of length 15 m and uniform cross-section $6.0 \times 10^{-7}\ \text{m}^2$ has a meaThe statement "$V = IR$ is itself the statement of Ohm's law" is, according to the text, iCurrent through an area of cross-section is treated as a scalar quantity in this chapter eA Wheatstone bridge has arms AB = 100 $\Omega$, BC = 10 $\Omega$, CD = 5 $\Omega$, DA = 60In a Wheatstone bridge the unknown resistance is placed in the fourth arm. Known resistanc