निम्नलिखित में से कौन सा सुरक्षात्मक उपकरण स्वचालित रूप से शॉर्ट सर्किट और ओवरलोड दोनों के खिलाफ सुरक्षा प्रदान करता है?

In a standard Miniature Circuit Breaker (MCB), which component is specifically responsible for providing the time-delayed tripping action during an overload condition?

In a High Rupturing Capacity (HRC) fuse, the space surrounding the fuse element is filled with a powder such as silica sand. What is the primary role of this filling material during the interruption of a fault current?