Electromagnetic...

An alternating current generator has an internal resistance $$R_{g}$$ and an internal reactance $$X_{g}$$. It is used to supply power to a passive load consisting of a resistance $$R_{g}$$ and a reactance $$X_{L}$$. For maximum power to be delivered from the generator to the load, the value of $$X_{L}$$ is equal to

A pair of parallel conducting rails lie at right angle to a uniform magnetic field of $$2.0\ T$$ as shown in the figure. Two resistors $$10\ \Omega$$ and $$5\ \Omega$$ are to slide without friction along the rail. The distance between the conducting rails is $$0.1\ m$$. Then:

The current through an inductor of $$1\ H$$ is given by
$$ i=3t\ \sin { t }$$
The voltage across the inductor of $$1\ H$$ is:

A magnetic field given by $$B(t) = 0.2 t - 0.05 { t }^{ 2 }$$ tesla is directed perpendicular to the plane of a circular coil containing $$25$$ turns of radius $$1.8\ cm$$ and whose total resistance is $$1.5\ \Omega $$. The power dissipation at $$3\ s$$ is approximate.

The diagram below shows two coils A and B placed parallel to each other at a very small distance. Coil A is connected to an ac supply. G is a very sensitive galvanometer. When the key is closed -

Two conducting rings P and Q of radii and r and 2r rotate uniformly in opposite directions with centre of mass velocities 2 v and v respectively on a conducting surface S. There is a uniform magnetic field of magnitude B perpendicular to the plane of the rings. The potential difference between the highest points of the two rings is

Current $$1$$ in a long $$4y-$$axis is paced through a square metal frame of side $$2a$$ oriented in the $$y-z$$ p[lane a shown. The linear mass density of the frame is $$\lambda$$. A uniform magnetic field $$B$$ is now switched on along $$x-$$axis. Then the instantaneous angular acceleration of the frame will be:

In figure shown, wire $$P_{1}Q_{1}$$ and $$P_{2}Q_{2}$$, both are moving towards right with speed $$5\ cm/sec$$. Resistance of each wire is $$2\ \Omega$$ . Then current through $$19\ \Omega $$ resistor is:

When the current in a coil changes from 8 ampere to 2 ampere in $$3 \times 10^{-2}$$ second, the e.m.f. induced in the coil is 2 volt. The self inductance of the coil (in millinery) is

A circular wire $$ABC$$ and a straight conductor $$ADC$$ are carrying current $$i$$ and are kept or the magnetic field $$B$$ then considering points $$A$$ and $$C$$