The north pole of a magnet is brought down along the axis of a horizontal circular coil (figure). As a result the flux through the coil changes from $$0.4$$ Weber to $$0.9$$ Weber in an interval of half of a second. Find the average emf induced during this period. Is the induced current clockwise or anticlockwise as you look into the coil from the side of the magnet?
The induced emf is given as,
$$\varepsilon = - \dfrac{{d\phi }}{{dt}}$$
$$\varepsilon = - \dfrac{{\left( {0.9 - 0.4} \right)}}{{0.5}}$$
$$\varepsilon = - 1\;{\rm{V}}$$
Thus EMF produced is 1 V and will oppose the motion of magnet towards the coil. The direction of current will be anticlockwise in the coil and will behave as north pole of magnet.
A square frame of side $$10 cm$$ and a long straight wire carrying current $$1 A$$ are in the plane of the paper. Starting from close to the wire, the frame moves towards the right with a constant speed of $$10 ms^{-1}$$ (see figure). The e.m.f induced in the frame at the time the left arm is at $$x=10cm$$ from the wire is :
A coil of cross-sectional area $$A$$ having $$n$$ turns is placed in a uniform magnetic field $$B$$. When it is rotated with an angular velocity $$\omega$$, the maximum e.m.f. induced in the coil will be
A conducting square frame of side $$'a'$$ and a long straight wire carrying current $$I$$ are located in the same plane as shown in the figure. The frame moves to the right with a constant velocity $$'V'$$. The $$emf$$ induced in the frame will be proportional to
A current carrying infinitely long wire is kept along the diameter of a circular wire loop, without touching it. The correct statement(s) is(are)
Figure shows a conducting square loop placed parallel to the pole-faces of a ring magnet. The pole-faces have an area of $$1{ cm }^{ 2 }$$ each and the field between the poles is $$0.10T$$. The wires making the loop are all outside the magnetic field. If the magnet is removed in $$1.0s$$, what is the average emf induced in the loop?
Two identical coaxial circular loops carry a current I each circulating in the same direction If the loops approach each other, you will observe that
The mutual inductance of an induction coil is $$5H$$. In the primary coil, the current reduces from $$5A$$ to zero in $$10^{-3}$$s. What is the induced emf in the secondary coil?
A coil having an area $$A_0$$ is placed in a magnetic field which changes from $$B_0$$ to $$4B_0$$ in a time interval $$t$$. The e.m.f. induced in the coil will be
The magnetic flux linked with a coil is given by an equation $$\phi$$ (in webers) $$= 8t^2 + 3t + 5.$$ The induced e.m.f. in the coil at the fourth second will be
The magnetic flux $$\phi$$ linked with a conducting coil depends on time as $$\phi=4t^n +6$$ where n is a positive constant. The induced emf in the coil is e.