MHT CET · Physics · Magnetic Effects of Current
A circular coil of radius 'R' is carrying a current ' \(\mathrm{I}_{1}\) ' in anticlockwise sense. A long straight wire is carrying current ' \(\mathrm{I}_{2}\) ' in the negative direction of \(\mathrm{x}\) axis. Both are placed in the same plane and the distance between centre of coil and straight wire is 'd'. The magnetic field at the centre of coil will be zero for the value of 'd' equal to
- A \(\frac{\pi}{R}\left(\frac{\mathrm{I}_{1}}{\mathrm{I}_{2}}\right)\)
- B \(\frac{\pi}{R}\left(\frac{\mathrm{I}_{2}}{\mathrm{R}_{1}}\right)\)
- C \(\frac{\mathrm{R}}{\pi}\left(\frac{\mathrm{I}_{2}}{\mathrm{I}_{1}}\right)\)
- D \(\frac{\mathrm{R}}{\pi}\left(\frac{\mathrm{I}_{1}}{\mathrm{I}_{2}}\right)\)
Answer & Solution
Correct Answer
(C) \(\frac{\mathrm{R}}{\pi}\left(\frac{\mathrm{I}_{2}}{\mathrm{I}_{1}}\right)\)
Step-by-step Solution
Detailed explanation
(C)
Magnetic field at the centre due to coil
\(\begin{array}{l}
\mathrm{B}_{1}=\frac{\mu_{0} \mathrm{I}_{1}}{2 \mathrm{R}} \\
\mathrm{B}_{2}=\frac{\mu_{0} \mathrm{I}_{2}}{2 \pi \mathrm{d}} \\
\mathrm{B}_{1}=\mathrm{B}_{2} \\
\frac{\mu_{0} \mathrm{I}_{1}}{2 \mathrm{R}}=\frac{\mu_{0} \mathrm{I}_{2}}{2 \pi \mathrm{d}} \\
\mathrm{d}=\frac{\mu_{0} \mathrm{I}_{2}}{\mu_{0} \mathrm{I}_{1}} \frac{2 \mathrm{R}}{2 \pi} \\
\mathrm{d}=\frac{\mathrm{I}_{2} \mathrm{R}}{\mathrm{I}_{1} \pi}
\end{array}\)

Magnetic field at the centre due to coil
\(\begin{array}{l}
\mathrm{B}_{1}=\frac{\mu_{0} \mathrm{I}_{1}}{2 \mathrm{R}} \\
\mathrm{B}_{2}=\frac{\mu_{0} \mathrm{I}_{2}}{2 \pi \mathrm{d}} \\
\mathrm{B}_{1}=\mathrm{B}_{2} \\
\frac{\mu_{0} \mathrm{I}_{1}}{2 \mathrm{R}}=\frac{\mu_{0} \mathrm{I}_{2}}{2 \pi \mathrm{d}} \\
\mathrm{d}=\frac{\mu_{0} \mathrm{I}_{2}}{\mu_{0} \mathrm{I}_{1}} \frac{2 \mathrm{R}}{2 \pi} \\
\mathrm{d}=\frac{\mathrm{I}_{2} \mathrm{R}}{\mathrm{I}_{1} \pi}
\end{array}\)

See the Complete Solution
Get step-by-step explanations for this and 2.5 Lakh+ more JEE, NEET & CET questions.
- Unlock all solutions
- Practice the full chapter
- Track accuracy across PYQs
4.8 rated on Google Play · 14,000+ reviews
More questions from Physics
- When magnetic flux changes from \(6.5 \times 10^{-2} \mathrm{~Wb}\) to \(11 \times 10^{-2} \mathrm{~Wb}\) and the change in current is 0.03 A , the coefficient of mutual inductance will beMHT CET 2025 Easy
- For an ideal gas the density of the gas is \(\rho_0\) when temperature and pressure of the gas are \(T_0\) and \(\mathrm{P}_0\) respectively. When the temperature of the gas is \(2 \mathrm{~T}_0\), its pressure will be \(3 \mathrm{P}_0\). The new density will beMHT CET 2023 Medium
- A prism having refractive index \(\sqrt{2}\) and refracting angle \(30^{\circ}\) has one of the
refracting surfaces silvered. The beam of light incident on the other refracting
surface will retrace its path, if angle of incidence is \(\left[\sin \frac{\pi}{6}=0 \cdot 5\right]\)MHT CET 2020 Medium - A particle of mass 'm' moves along a circle of radius 'r' with constant tangential
acceleration. If kinetic energy 'E' of the particle becomes three times by the end of
third revolution after beginning of the motion then the magnitude of tangential
acceleration isMHT CET 2020 Easy - What are the values of the currents flowing in each of the following diode circuits \(\mathrm{X}\) and \(\mathrm{Y}\) respectively? (Assume that the diodes are ideal)
MHT CET 2021 Hard - A student is throwing balls vertically upwards such that he throws the \(2^{\text {nd }}\) ball when the \(1^{\text {st }}\) ball reaches maximum height. If he throws balls at an interval of 3 second, the maximum height of the balls is \(\left(\mathrm{g}=10 \frac{\mathrm{m}}{\mathrm{s}^2}\right)\)MHT CET 2021 Easy
More PYQs from MHT CET
- The order of the differential equation whose solution is \(y=a \cos x+b \sin x+c e^{-x}\), isMHT CET 2007 Easy
- The equation of a line passing through the point \((2,1,3)\) and perpendicular to the lines \(\frac{x-1}{1}=\frac{y-2}{2}=\frac{z-3}{3}\) and \(\frac{x}{-3}=\frac{y}{2}=\frac{z}{5}\) isMHT CET 2022 Medium
- Light of wavelength \(5000 Å\) is incident normally on a slit. The first minimum of the diffraction pattern is observed to lie at distance of \(5 \mathrm{~mm}\) from the central maximum on a screen placed at a distance of \(2 \mathrm{~m}\) from the slit. The width of the slit.isMHT CET 2023 Medium
- If \(\tan ^{-1}(x+2)+\tan ^{-1}(x-2)-\tan ^{-1}\left(\frac{1}{2}\right)=0\), then one value of \(x\) isMHT CET 2024 Medium
- \(\int \frac{\sin 2 x}{(a+b \cos x)^2} d x=\)MHT CET 2025 Medium
- What is the value of \(\Delta \mathrm{H}-\Delta \mathrm{U}\) for the following reaction? \(2 \mathrm{C}_{(\mathrm{s})}+3 \mathrm{H}_{2(\mathrm{~g})} \rightarrow \mathrm{C}_2 \mathrm{H}_{6(\mathrm{~g})}\)MHT CET 2023 Easy