Electromagnetic...

A square wire frame of side $$a$$ is placed a distance $$b$$ away from a long straight conductor carrying current $$I$$. The frame has resistance $$R$$ and self inductance $$L$$. The frame is rotated by $$180^o$$ about OO' as shown in figure. Find the electric charge flown through the frame.

Find the inductance of a solenoid of length $$l_0$$, made of Cu windings of mass $$m$$. The winding resistance is equal to $$R$$. The diameter of solenoid << $$l$$. $$\rho_0$$ is resistivity of Cu and $$\rho$$ is density of the Cu.

Consider the situation shown. The wire AB is sliding on fixed rails with a constant velocity. If the wire AB is replaced by semi-circular wire, the magnitude of induced e.m.f will

A metallic rod of length $$l$$ is hinged at the point $$M$$ and is rotating about an axis perpendicular to the plane of paper with a constant angular velocity $$\omega$$. A uniform magnetic field of intensity $$B$$ is acting in the region (as shown in the figure) parallel to the plane of paper. The potential difference between the points $$M$$ and $$N$$.

A conducting rod of length $$l$$ falls vertically under gravity in a region of uniform magnetic field $$\vec { B } $$. The field vectors are inclined at an angle $$\theta$$ with the horizontal as shown in figure. If the instantaneous velocity of the rod is $$v$$, the induced emf in the rod $$ab$$ is:

The potential difference across a $$150mH$$ inductor as a function of time is shown in figure. Assume that the initial value of the current in the inductor is zero. What is the current when $$t=4.0ms$$?

An alternating current $$I$$ in an inductance coil varies with time $$t$$ according to the graph as shown:
Which one of the following graphs gives the variation of voltage with time?

A loop of area $$1{m}^{2}$$ is placed in a magnetic field $$B=2T$$, such that plane of the loop is parallel to the magnetic field. If the loop is rotated by $${180}^{o}$$, the amount of net charge passing through any point of loop, if its resistance is $$10\Omega$$ is :

A semi-circular conducting ring $$acb$$ of radius $$R$$ moves with constant speed $$v$$ in a plane perpendicular to uniform magnetic field $$B$$ as shown in figure. Identify the correct statement

A straight conducting rod $$PQ$$ is executing SHM in $$xy$$ plane from $$x=-d$$ to $$x=+d$$. Its mean position is $$x=0$$ and its length is along y-axis. There exists a uniform magnetic field $$B$$ from $$x=-d$$ to $$x=0$$ pointing inward normal to the paper and from $$x=0$$ to $$=+d$$ there exists another uniform magnetic field of same magnitude $$B$$ but pointing outward normal to the plane of the paper. At the instant $$t=0$$, the rod is at $$x=0$$ and moving to the right. The induced emf $$(\varepsilon )$$ across the rod $$PQ$$ vs time $$(t)$$ graph will be