The charge which will flow through a galvanometer of resistance $200 \Omega$ connected to a $400 \Omega$ circular coil of $1000$ turns wound on a wooden stick $20 \ mm$ in diameter,if a magnetic field $B=0.012 \ T$ parallel to the axis of the stick is decreased suddenly to zero,is nearly: (in $\mu C$)

The magnetic flux (in weber) in a closed circuit of resistance $20 \ \Omega$ varies with time $t$ (in seconds) according to the equation $\phi = 5t^2 - 6t + 9$. The magnitude of the induced current at $t = 0.2 \ s$ is: (in $A$)

$A$ coil has an area of $0.05\,m^2$ and it has $800\,turns$. It is placed perpendicularly in a magnetic field of strength $4 \times 10^{-5}\,Wb/m^2$. It is rotated through $90^o$ in $0.1\,s$. The average emf induced in the coil is ........... $V.$

As shown in the figure,a magnet is moved with a fast speed towards a coil at rest. Due to this,the induced electromotive force,induced current,and induced charge in the coil are $E$,$I$,and $Q$ respectively. If the speed of the magnet is doubled,which of the following statements is incorrect?

When two coaxial coils having the same current in the same direction are brought closer to each other,what happens to the value of the current in both coils?

$A$ circular loop made of thin copper wire of mass $m$ is placed in a uniform magnetic field such that the plane of the loop is perpendicular to the magnetic field. If $d$ and $\rho$ are the density and resistivity of copper respectively and the magnetic field varies at a constant rate of $\frac{dB}{dt}$,then the induced current in the loop is . . . . . .