List of top Physics Questions on Magnetic Effects of Current and Magnetism asked in UP Board XII

A charge \( q \) enters with speed \( v \) in the direction of magnetic field \( B \). The force on the charge in magnetic field will be:
What is meant by magnetic effect of electric current? Find the expression for the force acting between two parallel current-carrying conducting wires. On this basis, define the unit of electric current 'ampere'.
Write down the equation for Lorentz force. An electron passes undeviated from a place where an electric field \(5 \times 10^4~\text{V/m}\) and magnetic field of \(5 \times 10^{-2}~\text{weber/m}^2\) are applied. Calculate the velocity of the electron.
A charge \( q \) enters with speed \( v \) in the direction of magnetic field \( B \). The force on the charge in magnetic field will be:
Write down Biot-Savart law and find the expression for the magnetic field produced by a current-carrying conductor of infinite length, on the basis of it.
State and prove Ampere's circuital law.
Obtain the formula for the magnetic force between two parallel long current carrying conductors and define 1 A of current with its help.
What is Ampere's circuital law? Using it, obtain the formula for the magnetic field produced due to a straight current-carrying conductor of infinite length.
Write down the formula for the force in vector form, acting on a moving charged particle in a uniform electric and magnetic fields. Obtain the formula for the radius of the path of the particle entering perpendicular to the magnetic field only. What is the law for the direction of force acting on the particle?
What is the principle of a moving coil galvanometer? Draw its neat labelled diagram. How is the sensitivity of the galvanometer increased?
Write down the unit of magnetic dipole moment.
Following charged particles are projected perpendicular in a uniform magnetic field with the same velocity. The maximum force is exerted on:
What is radial magnetic field ? Explain principle of moving coil galvanometer with the help of suitable diagram. How can its sensitivity be increased ?
Deduce the expression of intensity of magnetic field produced inside long current carrying solenoid with the help of Ampere's law.
A current of 10 A is flowing in a long wire along the positive Z-axis. Find the intensity of magnetic field at a point (10 cm, 0, 0).
Same current in same direction is flowing in two parallel wire with 0.06 metre distance apart with each other. The attractive force per metre length of \(3 \times 10^{-3}\) newton is working between the two. Determine the value of current flowing in each wire.
Electron is moving with speed of \(2 \times 10^6\) m/s in an orbit of radius \(5.0 \times 10^{-11}\) metre in hydrogen atom. Determine the magnetic moment of rotating electron.
i current is flowing in a wire shown in figure. What will be the value of magnetic field at O of semi-circle :
(i) Due to each length \(l\) of straight portion, (ii) Due to radius R of semi-circle ?
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Obtain the formula for the magnetic force between two parallel long current carrying conductors and define 1 A of current with its help.
What is Ampere's circuital law? Using it, obtain the formula for the magnetic field produced due to a straight current-carrying conductor of infinite length.
The magnetic susceptibility \( \chi \) of paramagnetic substance varies with absolute temperature \( T \) as:
Write down the formula for the force in vector form, acting on a moving charged particle in a uniform electric and magnetic fields. Obtain the formula for the radius of the path of the particle entering perpendicular to the magnetic field only. What is the law for the direction of force acting on the particle?
The area of a plane coil 1000 turns is 500 cm\(^2\) and it is held perpendicular to a uniform magnetic field of \(4 \times 10^{-4}\) weber/m\(^2\). It is turned through 180° angle in 0.1 second. Calculate the average induced e.m.f. produced in the coil.
Following charged particles are projected perpendicular in a uniform magnetic field with the same velocity. The maximum force is exerted on:
Write down the unit of magnetic dipole moment.