Advertisements
Advertisements
Question
Briefly explain various ways to increase the strength of the magnetic field produced by a given solenoid.
Advertisements
Solution
The magnetic field inside a current-carrying solenoid is given by
B = μ0nI
where n is the number of turns per unit length in the solenoid, and I is the current through the wire.
As a result, increasing the current or the number of loops per metre would result in an increase in the magnetic field in the solenoid. Because the iron core is a magnet and is magnetised, it contributes flux to the solenoid's flux, hence increasing the magnetic field intensity.
The magnetic field strength produced by the solenoid can be raised by
- By inserting soft iron into the solenoid,
- By increasing the number of coil turns,
- By increasing the flow of electricity through the solenoid.
APPEARS IN
RELATED QUESTIONS
State Ampere’s circuital law.
Using Ampere’s circuital law, obtain the expression for the magnetic field due to a long solenoid at a point inside the solenoid on its axis ?
In Ampere's \[\oint \vec{B} \cdot d \vec{l} = \mu_0 i,\] the current outside the curve is not included on the right hand side. Does it mean that the magnetic field B calculated by using Ampere's law, gives the contribution of only the currents crossing the area bounded by the curve?
Consider the situation described in the previous problem. Suppose the current i enters the loop at the points A and leaves it at the point B. Find the magnetic field at the centre of the loop.
A solid wire of radius 10 cm carries a current of 5.0 A distributed uniformly over its cross section. Find the magnetic field B at a point at a distance (a) 2 cm (b) 10 cm and (c) 20 cm away from the axis. Sketch a graph B versus x for 0 < x < 20 cm.
Two large metal sheets carry currents as shown in figure. The current through a strip of width dl is Kdl where K is a constant. Find the magnetic field at the points P, Q and R.
Find the magnetic field due to a long straight conductor using Ampere’s circuital law.
A straight wire of diameter 0.5 mm carrying a current of 1 A is replaced by another wire of 1 mm diameter carrying the same current. The strength of the magnetic field far away is ______.
Two concentric and coplanar circular loops P and Q have their radii in the ratio 2:3. Loop Q carries a current 9 A in the anticlockwise direction. For the magnetic field to be zero at the common centre, loop P must carry ______.
The given figure shows a long straight wire of a circular cross-section (radius a) carrying steady current I. The current I is uniformly distributed across this cross-section. Calculate the magnetic field in the region r < a and r > a.
