What will be the direction of current in the coil $A$ as the switch $S$ is closed?

The instantaneous magnetic flux associated with a closed loop of resistance $10 \ \Omega$ is given by $\phi = 2t^2 - 5t + 1$. The magnitude of the induced current at $t = 0.25 \ s$ will be . . . . . . . (in $A$)

$A$ coil having $n$ turns and resistance $R \, \Omega$ is connected with a galvanometer of resistance $4 \, R \, \Omega$. This combination is moved in time $t$ seconds from a magnetic field $W_1$ weber to $W_2$ weber. The induced current in the circuit is

$A$ magnet is brought towards a coil $(i)$ speedily and $(ii)$ slowly. What will be the induced $e.m.f.$ and induced charge, respectively?

$A$ 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 $e.m.f.$ induced in the coil is (in $, V$)

$A$ uniform magnetic field $B$ that is perpendicular to the plane of the page passes through the loops,as shown. The field is confined to a region of radius $a$,where $a < b$,and is changing at a constant rate. The induced $emf$ in the wire loop of radius $b$ is $\varepsilon$. What is the induced $emf$ in the wire loop of radius $2b$?