Question
Give brief information about the solenoid.
✓
Answer
→Solenoid : "A helical coil consisting of closely wound turns of insulated conducting wire is called a solenoid."
→If the length of a solenoid is very large as compared to its radius, the solenoid is called long solenoid.
→Solenoid consists of a long wire wound in the form of a helix where the turns are closely spaced. Hence, each turn can be considered as a circular loop.
→The total magnetic field of solenoid is the vector sum of the fields due to all the turns.
→Enamelled wires are used for winding to make turns insulated from each other.
(a) The magnetic field due to a section of the solenoid which has been stretched out for clarity. Only the exterior semicircular part is shown. Notice how the circular loops between neighbouring turns tend to cancel.
(b) The magnetic field of a finite solenoid.
→Figure shows the magnetic field lines for a finite solenoid.
→It is clear from the figure (a) that the magnetic field of the circular loop between two neighbouring turns cancel out each other (in opposite direction)
→From the figure (b), it can be seen that the magnetic field is uniform, strong and in the direction of its axis at the mid point P inside the solenoid.
→While the magnetic field at the outer mid point Q is weak and almost parallel to the axis of the solenoid.
→ As the solenoid is made longer it looks like a long cylindrical metal sheet.
→Here we assume that for a long solenoid, the magnetic field outside the solenoid is zero, while inside the magnetic field is parallel to the axis every where.
→If the length of a solenoid is very large as compared to its radius, the solenoid is called long solenoid.
→Solenoid consists of a long wire wound in the form of a helix where the turns are closely spaced. Hence, each turn can be considered as a circular loop.
→The total magnetic field of solenoid is the vector sum of the fields due to all the turns.
→Enamelled wires are used for winding to make turns insulated from each other.
(a) The magnetic field due to a section of the solenoid which has been stretched out for clarity. Only the exterior semicircular part is shown. Notice how the circular loops between neighbouring turns tend to cancel.
(b) The magnetic field of a finite solenoid.
→Figure shows the magnetic field lines for a finite solenoid.
→It is clear from the figure (a) that the magnetic field of the circular loop between two neighbouring turns cancel out each other (in opposite direction)
→From the figure (b), it can be seen that the magnetic field is uniform, strong and in the direction of its axis at the mid point P inside the solenoid.
→While the magnetic field at the outer mid point Q is weak and almost parallel to the axis of the solenoid.
→ As the solenoid is made longer it looks like a long cylindrical metal sheet.
→Here we assume that for a long solenoid, the magnetic field outside the solenoid is zero, while inside the magnetic field is parallel to the axis every where.
Need a full question paper?
Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.
Explore more
Similar questions
Answer the following questions:
A low voltage supply from which one needs high currents must have very low internal resistance. Why?
A low voltage supply from which one needs high currents must have very low internal resistance. Why?
A uniform electric field exists between two charged plates as shown in the fig. What should be the work done in moving a charge q along the closed rectangular path ABCDA?
The bob of a simple pendulum of length 1m has mass 100g and a speed of 1.4m/s at the lowest point in its path. Find the tension in the string at this instant.
Define activity of a sample of a radioactive substance. The value of the disintegration constant of a radioactive substance is $0.0693h^{-1}$. Find the time after which the activity of a sample of this substance reduces to one-half that of its present value.
→Write uses of X-rays.
Explain from where does the dissipated power in the resistor come form.
###
Write a short note on electric cell.
###
Write a short note on electric cell.
A coil of N turns is wound tightly in the form of a spiral whose internal and external radii $r_1$ are $r_2$ and respectively. Current $I$ is flowing through the coil, then calculate the magnetic field at the center.
→When are two objects just resolved? Explain. How can the resolving power of a compound microscope be increased? Use relevant formula to support your answer.
A light bulb and an open coil inductor are connected to an ac source through a key as shown in Fig. 7.9.
The switch is closed and after sometime, an iron rod is inserted into the interior of the inductor. The glow of the light bulb (a) increases; (b) decreases; (c) is unchanged, as the iron rod is inserted. Give your answer with reasons.
The switch is closed and after sometime, an iron rod is inserted into the interior of the inductor. The glow of the light bulb (a) increases; (b) decreases; (c) is unchanged, as the iron rod is inserted. Give your answer with reasons.
In double-slit experiment using light of wavelength 600 nm, the angular width of a fringe formed on a distant screen is 0.1º. What is the spacing between the two slits?