Which device is detonated by a source of electricity?

The correct choice is indeed the M6 Electric Blasting Cap. This type of detonator is specifically designed to be triggered by an electrical impulse. When a source of electricity is applied to the M6 Electric Blasting Cap, it initiates a small explosive charge that in turn detonates the main explosive material.

Electric blasting caps offer precise control over the timing of a blast and can significantly enhance safety, as they allow for the separation of the power source from the explosive charge until just before detonation. This capability is particularly useful in scenarios where a reliable ignition source is critical, such as in mining or construction operations.

The other options do not utilize an electric source for detonation. For example, the M7 Non-Electric Blasting Cap relies on shockwaves from a detonating cord or other means to initiate a blast rather than electricity. The M81 Fuse Ignitor is the manual initiator for non-electric blasting, typically used in conjunction with fuse cords that ignite via heat. MDI refers to a type of detonating cord which is also not initiated by electric means but relies on a continuous wave of detonation.

Thus, the M6 Electric Blasting Cap stands out as the only device in this context that is specifically detonated by