Consider the energy density in a solenoid at its centre and that near its ends. Which of the two is greater?

Consider the self-inductance per unit length of a solenoid at its centre and that near its ends. Which of the two is greater?

The magnetic field intensity due to a long solenoid at its end is

The energy density u/V of an ideal gas is related to its pressure P as

Two parallel-plate capacitors, one filled with air and the other with a dielectric, have the same geometric dimensions, are connected in parallel, and are charged to a certain potential difference. In which of the two capacitors is the electric field strength greater, in which is the electric displacement greater, in which is the energy density greater, and in which is the surface charge density on the plates greater?

A solenoid 60 cm long and of radius 4 cm has 3 layer of windings 300 turns each. A 2.3 cm long wire of mass 2.5g lies inside the solenoide near its centre normal to its axis, both the wire and the axis of the solenoid are in the horizontal plane. The wire is connected through two leads parallel to the axis of the solenoid to an external battery which supplies a current of 6A in the wire. What value of current (with appropriate sense of circulation) in the windings of the solenoid can support the weight of the wire?

What is the magnitude of force on a wire of length 0*04m placed inside a solenoid near its centre, making an angle of 30^@ with its axis? The wire carries a current of 12A and the magnetic field due to the solenoid is of magnitude 0*25T .

A wire carrying a current 15A and of length 4*0cm is placed inside a solenoid near its centre making an angle of 60^@ with the axis of solenoid, where the magnitude of the magnetic field due to the solenoid is 0*30T . What is the force on the wire?

A solenoid 50cm long has 4 layers of windings of 350 turns each. The radius of the lowest layer is 1*4cm . If the current carried is 6*0A , estimate the magnitude of magnetic flux density (i) near the centre of the solenoid on its axis, (ii) near the ends on its axis, (iii) outside the solenoid near its centre.