A wire of fixed length is wound on a solenoid of length ‘l ’ and radius ‘r ’. Its self inductance is found to be L. Now if same wire is wound on a solenoid of length l/2 and radius r/2 then the self inductance will be nL. Find the value of n.
The number of turns, cross-sectional area and length for four solenoids are given in the following table.
The solenoid with maximum self inductance is :
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In an ideal transformer, the voltage and the current in the primary are 200 volt and 2amp respectively. If the voltage in the secondary is 2000 volt. Then value of current (in Amp) in the secondary will be :
In a L-R growth circuit, inductance and resistance used are 1H and 20Ω respectively. If at t = 50 millisecond, current in the circuit is 3.165A then applied direct current emf (in volt) is :
A long coaxial cable consists of two thin walled conducting cylinders with inner radius 2cm and outer radius 8cm. The inner cylinder carries a steady current 1A, and the outer cylinder provides the return path for that current. The current produces a magnetic field between the two cylinders. Find the energy stored in the magnetic field for length 1m of the cable. Express answer in nJ (use ln2 = 0.7)
A uniform magnetic field exists in region given by A rod of length 5m is placed along y-axis is moved along x-axis with constant speed 1m/sec. Then induced emf (in volts) in the rod will be :
Figure shows a square loop of side 1m and resistance 1Ω. The magnetic field on left side of line PQ has a magnitude B = 1.0T. The work done (in Joule) in pulling the loop out of the field uniformly in 1s is
The magnetic field of a cylindrical magnet that has a pole-face radius 2.8cm can be varied sinusoidally between minimum value 16.8T and maximum value 17.2T at a frequency of Cross section of the magnetic field created by the magnet is shown. At a radial distance of 2cm from the axis find the amplitude of the electric field (in mN/C) induced by the magnetic field variation.
In the figure, a long thin wire carrying a varying current lies at a distance y above one edge of a rectangular wire loop of length L and width W lying in the x-z plane. If emf is induced in the loop. Find the value of (A+B+C)
In the figure shown ABCDEFGH is a square conducting frame of side 2m and resistance 1Ω/m·A uniform magnetic field B is applied perpendicular to the plane and pointing inwards. It increases with time at a constant rate of 10T/s. Find the rate at which heat in watt is produced in the circuit AB = BC = CD = BH.