
An infinitely long straight wire carrying current $I$ is bent in a planar shape as shown in the diagram. The radius of the circular part is $r$. The magnetic field at the centre $O$ of the circular loop is :

In the system shown below, $x(t)=\sin(t)u(t)$. In steady-state, the response $y(t)$ will be 
The time constant of the network shown in the figure is 
The parallel RLC circuit shown in the figure is in resonance. In this circuit, 
Current electricity is defined as the flow of electrons from one section of the circuit to another.
There are two types of current electricity as follows:
The current electricity whose direction remains the same is known as direct current. Direct current is defined by the constant flow of electrons from a region of high electron density to a region of low electron density. DC is used in many household appliances and applications that involve a battery.
The current electricity that is bidirectional and keeps changing the direction of the charge flow is known as alternating current. The bi-directionality is caused by a sinusoidally varying current and voltage that reverses directions, creating a periodic back-and-forth motion for the current. The electrical outlets at our homes and industries are supplied with alternating current.