Magnetism and M...

Three long parallel wires carrying steady currents $$20\ A, 10\ A,10\ A$$ are cut by a perpendicular plane in the vertices $$A$$ and $$B$$ and $$C$$ of a triangle in which angles $$B$$ and $$C$$ are equal. The current of $$20\ A$$ through $$A$$ is in opposite direction through $$B$$ and $$C$$, then:

An aircraft is flying at a level height in presence the magnetic field of the Earth. If an electric bulb is connected between the two extreme ends of the wings,

Consider the situation shown in figure. If the closed loop is completely enclosed in the circuit containing the switch, the closed loop will show____

A uniform magnetic field along a long cylindrical rod varies with time as $$ B = \alpha t $$ where $$ \alpha $$ is positive constant. the electric field inside the rod as a function of radial distance r from the central axis is proportional to 

An Indian ship with a vertical conducting mass navigates the Indian ocean in the latitude of magnetic equator. To induce the greatest emf in the mast, the ship should proceed:

A copper rod is bent into a semi-circle of radius a and at ends straight parts are bent along diameter of the semi-circle and are passed through fixed, smooth and conducting ring O and O' as shown in fig. A capacitor having capacitance C connected to the rings. The system is located in uniform magnetic field of induction B such that axis of  rotation OO' is perpendicular to the field direction. At initial moment of time t=0 plane of semi circle was normal to  the field direction and the semi-circle is set in rotation with constant angular velocity $$\omega$$. Neglect the resistance and inductance of the circuit. The current flowing through circuit as function of time is

Two long parallel conducting rails are placed in a uniform magnetic field. On one side, the rails are connected with a resistance R. Two rods MN and M'N' each having resistance r are placed as shown in fig. Now on the rods MN and M'N' forces are applied such that the rods move with constant velocity v.

If in the previous problem resistances of values $$R_1$$ and $$R_2$$ are connected on both ends as shown in Fig. The current I, flowing through resistance $$R_1$$ is given by

A standing wave $$y=2A \sin kx \cos \omega t$$ is set up in the wire AB fixed at both ends by two vertical walls. The region between the walls contains a constant magnetic field B. Now, answer the following question..

In the above equation, the time when the emf becomes maximum for the first time is 

A metal bar is moving with a velocity of $$v=5 cm s^{-1}$$ over a U-shaped conductor.AT $$t=0$$, the external magnetic field is 0.1 T directed out of the page and is increasing at a rate of  $$0.2 T s^{-1}$$. Take $$l= 5 cm$$ and $$ t=0, x=5 cm$$

The current flowing in the circuit is 

Two long parallel conducting rails are placed in a uniform magnetic field. On one side, the rails are connected with a resistance R. Two rods MN and M'N' each having resistance r are placed as shown in fig. Now on the rods MN and M'N' forces are applied such that the rods move with constant velocity v.

The current flowing through resistance R if the rod MN moves towards left and the rod M'N' moves towards the right is