How can one determine whether a toggle switch is turned on or off?

To determine whether the toggle switch is in the "on" or "off" position, you can visually inspect the switch itself or observe the status of the device or circuit it controls. The following are several methods for identifying the status of toggle switches:
Switching position: A toggle switch usually has a control lever or toggle lever that can move up and down or left and right. When the toggle switch is in the upper position or pushed to one side, it usually indicates the "open" position. On the contrary, when the elbow joint is in a lower position or pulled to the other side, it usually indicates a "closed" position. The physical position of the toggle switch can provide you with a visual indication of whether the switch is on or off.
Markings or labels: Some toggle switches have markings or labels near them.
Indicator light: In some cases, the toggle switch may contain an internal indicator light. These lights help determine the status of the switch. When the switch is in the "on" position, the indicator light usually lights up, providing visual confirmation of the switch's status. When the switch is in the "off" position, the light will remain off.
Equipment operation: If you toggle a switch to control a device or circuit, you can observe the behavior or function of the device to infer the position of the switch. For instance, if a switch controls a light bulb, when the light is on, it indicates that the switch is in the "on" position. If the light does not come on, it indicates that the switch is in the "off" position.
It should be noted that the exact appearance and indication method may vary depending on the specific toggle switch design, manufacturer and application. Therefore, if you are unsure about the status or operation of the switch, it is recommended that you refer to the switch's documentation or consult a professional.