NEET 2016 Question Paper - Phase-II Code XX Mock Test

A long wire carrying a steady current is bent into a circular loop of one turn. The magnetic field at the centre is $B$. It is then bent into a circular coil of $n$ turns. The magnetic field at the centre of this coil will be:

A bar magnet is hung by a cotton thread in a horizontal magnetic field and is in equilibrium. The energy required to rotate it by $60^{\circ }$ is $W$. Now the torque required to keep the magnet in this new position is:

An electron is moving in a circular path under the influence of a transverse magnetic field of $3.57\times 10^{-2}\text{T}$. If the value of $e/m$ is $1.76\times 10^{11}\text{C/kg}$, the frequency of revolution of the electron is:

Which of the following combinations should be selected for better tuning of an L-C-R circuit used for communication?

A uniform magnetic field is restricted within a region of radius $r$. The field changes with time at a rate $dB/dt$. Loop 1 of radius $R>r$ encloses the region and loop 2 of radius $R$ is outside the region. The e.m.f. generated is: