MCQ
When a current in a circular loop is equivalently replaced by a magnetic dipole:
  • A
    The pole strength m of each pole is fixed.
  • B
    The distance d between the poles is fixed.
  • The product md is fixed.
  • D
    None of the above.

Answer

Correct option: C.
The product md is fixed.
When we replace a circular current-carrying loop with a magnetic dipole to resemble field lines of the circular loop, the pole strength m and the distance between the poles are not fixed.

But the magnetic dipole moment of both systems is always fixed. It is the product of the magnetic moment and the distance between the poles. In other words, md is fixed.

A current loop of area A and current I can be replaced with a magnetic dipole of dipole moment md.

i.e. md = IA

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

Similar questions

A galvanometer coil of resistance $50 \,\Omega$, show full deflection of $100\,\mu A$. The shunt resistance to be added to the galvanometer, to work as an ammeter of range $10\, mA$ is
The ampere-sec stands for the unit of:
In given $LCR$ circuit, the voltage across the terminals of a resistance and current will be
If each resistance in the figure is of 9 W then reading of ammeter is
When two magnetic moments are compared using equal distance method the deflections produced are $45^{\circ}$ and $30^{\circ}$. If the length of magnets are in the ratio 1 : 2, the ratio of their pole strengths is
Uniform electric field of magnitude $ 100$ $V/m$ in space is directed along the line $y$ $=$ $3$ $+$ $x$. Find .........$V$ the potential difference between point $A (3, 1)$ $ \&$ $ B$ $ (1, 3)$
The energy band gap is maximum in
The amplitude modulated $(AM)$ radio wave bends appreciably round the corners of a $1m \times 1m$ board but the frequency modulated $(FM)$ wave only negligibly bends. If the average wavelengths of $AM$ and $FM$ waves are $\lambda_\text{a}$ and $\lambda_\text{f}:$
An electron enters the space between the plates of a charged capacitor as shown. The charge density on the plate is $\sigma $. Electric intensity in the space between the plates is $E$. A uniform magnetic field $B$ also exists in that space perpendicular to the direction of $E$. The electron moves perpendicular to both $\vec E$ and $\vec B$ without any change in direction. The time taken by the electron to travel a distance $\ell $ is the space is
A bar magnet of magnetic moment $200 \,A-m^2$ is suspended in a magnetic field of intensity $0.25 \,N/A-m$. The couple required to deflect it through $30^o$ is....$N-m$