Moving Charges and Magnetism · Physics · AP EAPCET
MCQ (Single Correct Answer)
Three rings, each with equal radius $r$ are placed mutually perpendicular to each other and each having centre at the origin of coordinate system. $I$ is current passing through each ring. The magnetic field value at the common centre is
An electron having kinetic energy of 100 eV circulates in a path of radius 10 cm in a magnetic field. The magnitude of magnetic field $$|\mathbf{B}|$$ is approximately [Mass of electron $$=0.5 \mathrm{~MeV} \mathrm{c}^{-2}$$, where c is the velocity of light].
A particle of mass $$2.2 \times 10^{-30} \mathrm{~kg}$$ and charge $$1.6 \times 10^{-19} \mathrm{C}$$ is moving at a speed of $$10 \mathrm{~km} \mathrm{~s}^{-1}$$ in a circular path of radius 2.8 cm inside a solenoid. The solenoid has $$25 \frac{\text { turns }}{\mathrm{cm}}$$ and its magnetic field is perpendicular to the plane of the particle's path. The current in the solenoid is
(Take, $$\mu_0=4 \pi \times 10^{-7} \mathrm{~Hm}^{-1}$$)
A toroid has a non ferromagnetic core of inner radius 24 cm and outer radius 25 cm , around which 4900 turns of a wire are wound. If the current in the wire is 12 A , the magnetic field inside the core of the toroid is
Two infinitely long wires each carrying the same current and pointing in $$+y$$ direction are placed in the $$x y$$-plane, at $$x=-2 \mathrm{~cm}$$ and $$x=1 \mathrm{~cm}$$. An electron is fired with speed $$u$$ from the origin making an angle of $$+45^{\circ}$$ from the $$X$$-axis. The force on the electron at the instant it is fired is
[$$B_0$$ is the magnitude of the field at origin due to the wire at $$x=1 \mathrm{~cm}$$ alone].
Two electrons, $$e_1$$ and $$e_2$$ of mass $$m$$ and charge $$q$$ are injected into the perpendicular direction of the magnetic field $$B$$ such that the kinetic energy of $$e_1$$ is double than that of $$e_2$$. The relation of their frequencies of rotation, $$f_1$$ and $$f_2$$ is
A wire of length $$L$$ metre carrying a current $$I$$ ampere is bent in the form of a circle. Magnitude of its magnetic moment is
What is the net force on the square coil?
In a co-axial, straight cable, the central conductor and the outer conductor carry equal currents in opposite directions. The magnetic field is zero
The magnetic field, of a given length of wire for single turn coil, at its centre is B, then its value for two turns coil for the same wire is
In which of the following case no force exerted by a magnetic field on a charge?
A long thin hollow metallic cylinder of radius R has a current i ampere. The magnetic induction B away from the axis at a distance r from the axis varies as shown in
