Which one of the following gives the value of the magnetic field according to Biot-Savart’s law?
1. | \(\frac{{i} \Delta {l} \sin (\theta)}{{r}^2} \) | 2. | \(\frac{\mu_0}{4 \pi} \frac{i \Delta {l} \sin (\theta)}{r} \) |
3. | \(\frac{\mu_0}{4 \pi} \frac{{i} \Delta{l} \sin (\theta)}{{r}^2} \) | 4. | \(\frac{\mu_0}{4 \pi} {i} \Delta {l} \sin (\theta)\) |
An element \(\Delta l=\Delta x \hat{i}\) is placed at the origin and carries a large current of \(I=10\) A (as shown in the figure). What is the magnetic field on the y-axis at a distance of \(0.5\) m?(\(\Delta x=1~\mathrm{cm}\))
1. | \(6\times 10^{-8}~\mathrm{T}\) | 2. | \(4\times 10^{-8}~\mathrm{T}\) |
3. | \(5\times 10^{-8}~\mathrm{T}\) | 4. | \(5.4\times 10^{-8}~\mathrm{T}\) |
A straight wire carrying a current of 12 A is bent into a semi-circular arc of radius 2.0 cm as shown in the figure. Considering the magnetic field B at the centre of the arc, what will be the magnetic field due to the straight segments?
The resistances of three parts of a circular loop are as shown in the figure. What will be the magnetic field at the centre of O
(current enters at A and leaves at B and C as shown)?
1.
2.
3.
4. 0
Which of the following graphs correctly represents the variation of magnetic field induction with distance due to a thin wire carrying current?
1. | 2. | ||
3. | 4. |
What is the magnetic field at point O in the figure?
1.
2.
3.
4.
Two identical long conducting wires \(\mathrm{AOB}\) and \(\mathrm{COD}\) are placed at a right angle to each other, with one above the other such that '\(O\)' is the common point for the two. The wires carry \(I_1\) and \(I_2\) currents, respectively.
Point '\(P\)' is lying at a distance '\(d\)' from '\(O\)' along a direction perpendicular to the plane containing the wires. What will be the magnetic field at the point \(P\)?
1. \(\frac{\mu_0}{2\pi d}\left(\frac{I_1}{I_2}\right )\)
2. \(\frac{\mu_0}{2\pi d}\left[I_1+I_2\right ]\)
3. \(\frac{\mu_0}{2\pi d}\left[I^2_1+I^2_2\right ]\)
4. \(\frac{\mu_0}{2\pi d}\sqrt{\left[I^2_1+I^2_2\right ]}\)
If the magnetic field at the centre of the circular coil is B0, then what is the distance on its axis from the centre of the coil where \(B_x=\frac{B_0}{8}~?\)
(R= radius of the coil)
1. | \(R \over 3\) | 2. | \(\sqrt{3}R\) |
3. | \(R \over \sqrt3\) | 4. | \(R \over 2\) |
A circular coil is in the y-z plane with its centre at the origin. The coil carries a constant current. Assuming the direction of the magnetic field at x = – 25 cm to be positive, which of the following graphs shows the variation of the magnetic field along the x-axis?
1. | 2. | ||
3. | 4. |
A current loop consists of two identical semicircular parts each of radius \(R\), one lying in the x-y plane, and the other in the x-z plane. If the current in the loop is \(i\), what will be the resultant magnetic field due to the two semicircular parts at their common centre?
1. | \( \frac{\mu_0 i}{2 \sqrt{2} R} \) | 2. | \( \frac{\mu_0 i}{2 R} \) |
3. | \( \frac{\mu_0 i}{4 R} \) | 4. | \( \frac{\mu_0 i}{\sqrt{2} R}\) |