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 \(y\text-\)axis at a distance of \(0.5\) m? \((\Delta x=1~\text{cm})\)
1. | \(6\times 10^{-8}~\text{T}\) | 2. | \(4\times 10^{-8}~\text{T}\) |
3. | \(5\times 10^{-8}~\text{T}\) | 4. | \(5.4\times 10^{-8}~\text{T}\) |
1. | \(0\) | 2. | \(1.2\times 10^{-4}~\text{T}\) |
3. | \(2.1\times 10^{-4}~\text{T}\) | 4. | None of these |
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. | \(\dfrac{\mu_{0} I}{6 a}\) | 2. | \(\dfrac{\mu_{0} I}{3 a}\) |
3. | \(\dfrac{2\mu_{0} I}{3 a}\) | 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. | \(\dfrac{\mu_{0} I}{4 \pi r}\) | 2. | \(\dfrac{\mu_{0} I}{4 \pi r} + \dfrac{\mu_{0} I}{2 \pi r}\) |
3. | \(\dfrac{\mu_{0} I}{4 r} + \dfrac{\mu_{0} I}{4 \pi r}\) | 4. | \(\dfrac{\mu_{0} I}{4 r} - \dfrac{\mu_{0} I}{4 \pi r}\) |
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. | \(\dfrac{\mu_0}{2\pi d}\left(\dfrac{I_1}{I_2}\right )\) | 2. | \(\dfrac{\mu_0}{2\pi d}\left[I_1+I_2\right ]\) |
3. | \(\dfrac{\mu_0}{2\pi d}\left[I^2_1+I^2_2\right ]\) | 4. | \(\dfrac{\mu_0}{2\pi d}\sqrt{\left[I^2_1+I^2_2\right ]}\) |
1. | \(R \over 3\) | 2. | \(\sqrt{3}R\) |
3. | \(R \over \sqrt3\) | 4. | \(R \over 2\) |
1. | 2. | ||
3. | 4. |
1. | \( \dfrac{\mu_0 i}{2 \sqrt{2} R} \) | 2. | \( \dfrac{\mu_0 i}{2 R} \) |
3. | \( \dfrac{\mu_0 i}{4 R} \) | 4. | \( \dfrac{\mu_0 i}{\sqrt{2} R}\) |