$A$ conducting ring is placed around the core of an electromagnet as shown in the figure. When key $K$ is pressed,the ring

Two identical circular loops of metal wire are lying on a table without touching each other. Loop $A$ carries a current which increases with time. In response,the loop $B$:

$A$ long solenoid with $15$ turns per $cm$ has a small loop of area $2.0 \,cm^2$ placed inside the solenoid normal to its axis. If the current carried by the solenoid changes steadily from $2.0 \,A$ to $4.0 \,A$ in $0.1 \,s$, the induced emf in the loop while the current is changing is nearly [Take $\pi=3.14$].

$A$ circular coil has $100$ turns,radius $3 \ cm$ and resistance $4 \Omega$. This coil is co-axial with a solenoid of $200$ turns/cm and diameter $4 \ cm$. If the solenoid current is decreased from $2 \ A$ to zero in $0.04 \ s$,then the current induced in the coil is

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 $A$)

The coil and magnet are moved in the same direction with the same speed $V$. The induced e.m.f. is