The pattern of magnetic field lines around a current-carrying solenoid is similar to that around a bar magnet. In both cases, the field lines form closed loops. Inside the solenoid, the lines run parallel to its axis, creating a strong, uniform magnetic field. Outside the solenoid, the field lines resemble those around a bar magnet, extending from one pole to the other. The key difference is that a solenoid can be turned on and off by controlling the current flow, making it a controllable electromagnet, while a bar magnet has a permanent magnetic field.