The magnetic field at a perpendicular distance of 2 cm from an infinite straight current carrying conductor is 2x10^-6 T. The current in the wire is

A positive charge is moving towards an observer. The direction of magnetic induction lines is 

If a copper wire carries a direct current, the magnetic field associated with the current will be

Current carrying wire produces

A circular coil of n turns and radius r carries a current I. The magnetic field at the centre is 

The north pole of a magnet is brought near a stationary negatively charged conductor. Will the pole experience any force?

What is the unit of magnetic field strength in cgs system and SI? State the relation between them.

An electron moving with a velocity of 10⁷ ms^-1 enters a uniform magnetic field of 1 T, along a direction parallel to the field. What would be its trajectory?

Explain, how moving charge is a source of magnetic field.

What are the dimensions of \({ \mu }_{ o }/4\pi \) ?

Suppose a helical spring is suspended from the roof of a room and very small weight is attached to its lower end what will happen to the spring when a current is passed through it?Give reason to support your answer?

Out of Voltmeter and Millivoltmeter, which has the higher resistance?

Proton is moving along the axis of a solenoid carrying current of 2 A and 50 number of turns per unit length. What will be the force acting on the particle

Out of Ammeter and Milliammeter, which has the higher resistance?

What will be the direction of magnetic field at point O

Write the relation for the force \(\overset { \rightarrow }{ F } \) acting on a charge carrier q moving with a velocity \(\overset { \rightarrow }{ v } \) through a magnetic field \(\overset { \rightarrow }{ B } \)  in vector notation. Using this relation, deduce the conditions under which this force will be (i) maximum (ii) minimum.

What is magnetic flux density? Define its units and give its dimensions.

In what respect does a wire carrying a current differ from a wire, which carries no current?

A current of one ampere is passed through a straight wire of length 2.0 metre. Find the magnetic field at a point in air at a distance 3 metre from one end of wire but lying on the axis of the wire.

Write the relation for the magnetic field induction at a point due to a linear conductor carrying current and hence deduce the relation for the magnetic field induction at a point due to a very long linear conductor carrying current.

Find the force on a wire (of negligible mass) of length 4.0 cm placed inside a solenoid near its centre, making an angle of 60^o with its axis.  The wire carries a current of  12 A and magnetic field due to solenoid has a magnitude of 0.25 T.  Find also the direction of the force experienced by the wire.

A voltmeter reads 5.0 V at full scale deflection and is graded according to its resistance per volt at full scale deflection as 2000 \(\Omega\)/V.  How will you convert it into a voltmeter that reads 15V at full scale deflection?

A straight horizontal conducting rod of length 0.45m and mass 60g is suspended by two vertical wires at its ends.  A current of 5.0 A is set up in the rod though the wires.
(a) What magnetic field should be set up normal to the conductor in order that the tension in the wires is zero?
(b) What will be the total tension in the wires if the direction of current is reversed keeping the magnetic field same as before? (Ignore the mass of the wires.) g = 9.8 ms^-2.

Assume the dipole model for earth's magnetic field B which by \({ B }_{ v }=\)vertical component of magnetic field = \(\frac { { \mu }_{ 0 } }{ 4\pi } \frac { 2M\cos { \theta } }{ { r }^{ 3 } } { B }_{ H }=\) Horizontal component of magnetic field = \(\frac { { \mu }_{ 0 } }{ 4\pi } \frac { 2M\sin { \theta M } }{ { r }^{ 3 } } ,\theta ={ 90 }^{ \circ }=\) lattitude as measured from magnetic equator. Find loci of points for which
(i) \(\left| B \right| \) is minimum
(ii) dip angle is zero and
(iii) dip angle is\(\pm { 45 }^{ \circ }\).

A circular loop of 2 turns carries a current of 5.0 A. If the magnetic field at the centre of loop is 0.40 mT, find the radius of the loop.