MCQ (Single Correct Answer)
Two long conductors separated by a distance '$$\mathrm{d}$$' carry currents $$I_1$$ and $$I_2$$ in the same direction. They exert a force '$$F$$' on e...
A circular arc of radius '$$r$$' carrying current '$$\mathrm{I}$$' subtends an angle $$\frac{\pi}{16}$$ at its centre. The radius of a metal wire is u...
A cylindrical magnetic rod has length $$5 \mathrm{~cm}$$ and diameter $$1 \mathrm{~cm}$$. It has uniform magnetization $$5.3 \times 10^3 \mathrm{~A} /...
Two parallel wires of equal lengths are separated by a distance of $$3 \mathrm{~m}$$ from each other. The currents flowing through $$1^{\text {st }}$$...
An electron is projected along the axis of circular conductor carrying current I. Electron will experience
The magnetic field at the centre of a circular coil of radius '$$R$$', carrying current $$2 A$$ is '$$B_1$$'. The magnetic field at the centre of anot...
Two wires $$2 \mathrm{~mm}$$ apart supply current to a $$100 \mathrm{~V}, 1 \mathrm{~kW}$$ heater. The force per metre between the wires is ( $$\mu_0=...
Two long parallel wires carrying currents $$8 \mathrm{~A}$$ and $$15 \mathrm{~A}$$ in opposite directions are placed at a distance of $$7 \mathrm{~cm}...
Electron of mass '$$\mathrm{m}$$' and charge '$$\mathrm{q}$$' is travelling with speed '$$v$$' along a circular path of radius '$$R$$', at right angle...
10 A current is flowing in two straight parallel wires in the same direction. Force of attraction between them is $$1 \times 10^{-3} \mathrm{~N}$$. If...
The magnetic field at a point $$\mathrm{P}$$ situated at perpendicular distance '$$R$$' from a long straight wire carrying a current of $$12 \mathrm{~...
A long straight wire carrying a current of $$25 \mathrm{~A}$$ rests on the table. Another wire PQ of length $$1 \mathrm{~m}$$ and mass $$2.5 \mathrm{~...
A, B and C are three parallel conductors of equal lengths carrying currents $$\mathrm{I}, \mathrm{I}$$ and $$2 \mathrm{I}$$ respectively. Distance bet...
Magnetic moment of revolving electron of charge (e) and mass (m) in terms of angular momentum (L) of electron is :
The magnetic flux near the axis and inside the air core solenoid of length $$60 \mathrm{~cm}$$ carrying current '$$\mathrm{I}$$' is $$1.57 \times 10^{...
A charge moves with velocity '$$V$$' through electric field $$(E)$$ as well as magnetic field (B). then the force acting on it is
A long solenoid carrying a current produces a magnetic field B along its axis. If the number of turns per $$\mathrm{cm}$$ is doubled and the current i...
A metal conductor of length $$1 \mathrm{~m}$$ rotates vertically about one of its ends at an angular velocity of $$5 \mathrm{~rad} / \mathrm{s}$$. If ...
Two wires carrying currents $$5 \mathrm{~A}$$ and $$2 \mathrm{~A}$$ are enclosed in a circular loop as shown in the figure. Another wire carrying a cu...
The magnetic field at the centre of a current carrying circular coil of area 'A' is 'B'. The magnetic moment of the coil is ( $$\mu_0=$$ permeability ...
The relation between magnetic moment 'M' of revolving electron and principle quantum number 'n' is
If the charge to ratio of an electron is 'A' C/kg, then the gyromagnetic ratio of an orbital electron in C/kg is
The magnetic field intensity 'H' at the centre of a long solenoid having 'n' turns per unit length and carrying a current 'I', when no material is kep...
An electron (e) moves in circular orbit of radius 'r' with uniform speed 'V'. It produces magnetic field 'B' at the centre of circle. The magnetic fie...