Following figures show the arrangement of bar magnets in different configuration. Each
magnet has magnetic dipole moment \[\overrightarrow{m}\] . Which configuration has highest net magnetic dipole moment?

A proton, deutron and α-particle are accelerated by same potential, enters in uniform
magnetic field perpendicularly. Ratio of radii of circular path respectively :

If a long hollow copper pipe carries a direct current, the magnetic field associated with the current will be :

In a co-axial straight cable, the central conductor and the outer conductor have equal currents in opposite directions. The magnetic induction is zero :

A solenoid consists of 100 turns of wire and has a length of 10.0cm. The magnetic field inside the solenoid when it carries a current of 0.500 A will be :

Two particles X and Y having equal charges, after being accelerated through the same potential
difference, enter a region of uniform magnetic field and describe circular paths of radii R1 and
R2 respectively. The ratio of masses of X and Y is :

A beam of electrons is projected horizontally to the right. A straight conductor carrying a current is supported parallel to the electron beam and above it. If the current in the conductor is from left to right, what will be the effect on the electron beam ?

A uniform electric field and a uniform magnetic field are produced, pointed in the same direction. An electron is projected with its velocity pointed in the same direction :

An electron moving with a speed u along the positive x-axis at y = 0 enters in a region of
uniform magnetic field \[\overrightarrow{B}=-B_{0}\hat{k}\] which exists to
the right of y-axis. The electron exits from the region after some time with speed v at coordinate
y, then :

A length of wire carries a steady current. It is bent first to form a circular plane coil of one turn. The same length is now bent more sharply to give a double loop of smaller radius. The magnetic field at the centre caused by the same current is :