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. |
The magnetic field at center due to the orbital motion of the electron in the hydrogen atom is :
1. 12.5 tesla
2. 5 tesla
3. 24 tesla
4. 1 tesla
A long solenoid has 800 turns per meter length of the solenoid. A current of 1.6 A flows through it. The magnetic induction at the end of the solenoid on its axis is:
1.
2.
3.
4.
An infinitely long straight conductor is bent into the shape as shown in the figure.
It carries a current of i amperes and the radius of the circular loop is r metres. What will be the magnetic induction at its centre?
1.
2.
3. Zero
4. Infinite
A current \(i\) ampere flows in a circular arc of wire whose radius is \(R,\) which subtend an angle radian at its centre. The magnetic induction \(B\) at the centre is:
1. \(\frac{\mu_0i}{R}\)
2. \(\frac{\mu_0i}{2R}\)
3. \(\frac{2\mu_0i}{R}\)
4. \(\frac{3\mu_0i}{8R}\)
A straight section PQ of a circuit lies along the X-axis from x= to x= and carries a steady current i. The magnetic field due to the section PQ at a point X = + a will be:
1. Proportional to a 2. Proportional to
3. Proportional to 4. Zero
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 straight horizontal parallel wires carry the same current in the same direction, and d is the distance between them. You are given a small magnetic needle that is freely suspended. Which of the following positions will have the needle's orientation independent of the magnitude of the current in the wires?
1. | At a distance d/2 from any of the wires in any plane. |
2. | At a distance d/3 from any of the wires in the horizontal plane. |
3. | Anywhere on the circumference of a vertical circle of radius d and centre halfway between the wires. |
4. | At points halfway between the wires in the horizontal plane. |
A circular coil of radius R carries an electric current. The magnetic field due to the coil at a point on the axis of the coil located at a distance r from the centre of the coil, such that r >> R, varies as
1.
2.
3.
4.
The magnetic induction due to an infinitely long straight wire carrying a current \(i\) at a distance \(r\) from the wire is given by:
1. \(
B =\frac{\mu_0}{4 \pi} \frac{2 i}{r}
\)
2. \(B =\frac{\mu_0}{4 \pi} \frac{r}{2 i}
\)
3. \(B =\frac{4 \pi}{\mu_0} \frac{2 i}{r}
\)
4. \(B =\frac{4 \pi}{\mu_0} \frac{r}{2 i}\)