Which one of the following gives the value of the magnetic field according to Biot-Savart’s law?
1.
2.
3.
4. \(\frac{\mu_0}{4 \pi} \mathrm{i} \Delta \mathrm{l} \sin (\theta)\)
To maximise the magnetic field caused by a small element of a current-carrying conductor at a point, the angle between the element and the line connecting the element to the point P must be:
1. 0º
2. 90º
3. 180º
4. 45º
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?
Which one of the following expressions represents Biot-Savart's law? Symbols have their usual meanings.
1.
2.
3.
4.
A long wire carrying a steady current is bent into a circular loop of one turn. The magnetic field at the centre of the loop is B. It is then bent into a circular coil of n turns. What will the magnetic field be at the centre of this n-turn coil?
1. nB
2. n2B
3. 2nB
4. 2n2B
The magnetic induction at point P, which is 4 cm from a long current-carrying wire is 10-8 Tesla. What would be the field of induction at a distance of 12 cm from the same current?
1. | 3.33 x 10-9 Tesla |
2. | 1.11 x 10-4 Tesla |
3. | 3 x 10-3 Tesla |
4. | 9 x 10-2 Tesla |
Two similar coils of radius R are lying concentrically with their planes at right angles to each other. The currents flowing in them are I and 2I, respectively. What will be the resultant magnetic field induction at the centre?
1.
2.
3.
4.
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. |