ضُرِبَ is a passive perfect verb: “he/it was struck,” reporting a past event. مَضْرُوبٌ is a passive participle: “struck,” a derived noun that can describe a person or thing.
Word / formMeaning / explanation
نُصِرَhe was helped.
مَنْصُورٌhelped or supported.
سُمِعَit was heard.
مَسْمُوعٌheard.
Both carry a passive relationship to an action, but the finite verb conveys an event in time and the participle has nominal form and function.