Tag: magnetic flux density

The magnetic flux density at a point distant $d$ from a long straight current carrying conductor is $B$, then its value at distance $d/2$ will be:

The magnetic needle of a tangent galvanometer is deflected at an angle $30$ due to a magnet. The horizontal component of earth's magnetic field $0.34\times 10^{-4}T$ is along the plane of the coil. The magnetic intensity is:

A sphere of radius $R$ and charge $Q$ is placed inside an imaginary sphere of radius $2R$. Whose center coincides with the given sphere. The flux related to the imaginary sphere is:

The flux linked with a coil changes with time according to the equation $\phi$ = a$t^2$ +bt +c. Then SI unit of a is 

In a circuit a coil of resistance $2\,\Omega$, then magnetic flux charges from $2.0\,Wb$ to $10.0\,Wb$ in $0.2\ sec.$ The charge flow in the coil during this time is:

Two coils $A$ and $B$ are wound on the same iron  core as shown in figure. The number of turns in the coil $A$ and $B$ are $N _{A}$ and $N _{B}$ respectively. Identity the correct statement 

The magnetic flux through a stationary loop with resistance R varies during the interval of time T as $\phi  = at(T - t)$ ./ The heat generated during this time neglecting the inductance of the loop will be :

A circular disc of radius $0.2$m isplaced in a uniform magnetic field of induction $\dfrac{1}{\pi}\left(\dfrac {Wb}{m^2}\right)$ in such a way that its axis ,makes an angle of $60^o$ with $\xrightarrow {B}$. The magnetic flux linked with the disc is

The magnetic flux through a coil is $4\times 10^{-4} W/b/m^2$ at time $t=0$.It reduces to $10\%$ of its original value in 't' seconds.If the induced e.m.f is $0.72 m V,$ then the time t is:

In a uniform electric field $\vec {E}$ an imaginary cube of edge length $a$ is considered as shown. The outward flux linked with cube surface will be :