The negative sign in Faraday's law represents which fact?

$A$ square conducting loop is placed near an infinitely long current-carrying wire with one edge parallel to the wire as shown in the figure. If the current in the straight wire is suddenly halved, which of the following statements will be true? "The loop will .......".

The direction of induced e.m.f. during electromagnetic induction is given by

If a coil of $40$ turns and area $4 \, cm^2$ is suddenly removed from a magnetic field,it is observed that a charge of $2 \times 10^{-4} \, C$ flows through the coil. If the resistance of the coil is $80 \, \Omega$,the magnetic flux density in $Wb \, m^{-2}$ is:

The following figure shows planar loops of different shapes moving into or out of a region of a magnetic field which is directed normal to the plane of the loop,away from the reader. Determine the direction of the induced current in each loop using Lenz's law.

$A$ circular coil of radius $10 \; cm$, $500$ turns, and resistance $2 \; \Omega$ is placed with its plane perpendicular to the horizontal component of the earth's magnetic field. It is rotated about its vertical diameter through $180^{\circ}$ in $0.25 \; s$. The induced e.m.f. in the coil is (Take $B_H = 3.0 \times 10^{-5} \; T$).