MRY Tower Local Controller reported TRACON handed off two aircraft with a large overtake that required immediate action to resolve. The reporter stated TRACON routinely hands off aircraft to them that are in confliction.

Narrative

Aircraft X; was on a Visual Approach to MRY about 6 mile final; cleared to land on my frequency. Aircraft Y; was on RNAV Y 28L approach and was rapidly closing on Aircraft X. Aircraft X was at 140 knots; Aircraft Y was 250 knots and descending rapidly at Aircraft X's altitude and location. I saw there was a serious collision hazard about to occur so I keyed up to see if Aircraft Y was on my frequency by chance. He was not. I was about to push the button to key up to NCT to break for control and make sure they were handling it when Aircraft Y checked on my frequency. I was shocked they were handed off to me in a near imminent collision situation. I asked Aircraft Y if they had traffic in sight; 12 o clock; less than a mile; 2500 descending in sight. They did not. I asked if they had the airport in sight; as I was going through my options mentally how to separate these aircraft as Aircraft Y was below the MVA.I thought if he reported the airport in sight I would break him off to the north downwind for a Visual Approach. Aircraft Y did not answer. NCT then chimes in repeatedly on the shout line; as I'm trying fix this situation. The aircraft are around a mile apart; 200 feet vertical separation with Aircraft Y higher than Aircraft X; and Aircraft Y 110 knots faster. I answer the shout line only because I thought NCT would actually be giving me alternate climbout instructions which they did not. Instead they gave useless information about how he broke Aircraft Y off the approach; which was later found to be false. He simply shipped Aircraft Y to me in a significant event/separation loss status. I asked them what they wanted me to do with Aircraft Y; which they replied to climb them on runway heading to 5000 ft. I go back to Aircraft Y and tell them to climb to 5000 ft. present heading; which they did not respond. I again tell them to climb to 5000 ft. heading 280; approach clearance cancelled; climb to 5000 ft. heading 280. Aircraft Y complies. Around 20 minutes earlier than this incident; NCT sent me a strikingly similiar situation with a regional jet and a business jet; and NCT does this quite frequently. MRY Supervisor calls the Ops Manager at NCT to have them check into this event to which the Ops Manager tells us to look out the window and apply tower visual separation; what is going on down there at MRY.First of all; tower visual separation does not apply to an aircraft on an IFR approach procedure. Next; both aircraft were 5 to 6 miles east of MRY and nearly impossible to see with the naked eye; though I had the lead aircraft; Aircraft X; in sight. The Aircraft Y was so close he blended in with the lead aircraft. Next after the Conflict Alarm is going off my attention is on the radar scope trying to figure my options to pry these aircraft apart before collision that I was handed from NCT. Both aircraft are below the MVA; the lead aircraft is on a Visual Approach; the trailing aircraft is on an instrument approach. My only legal option for the trailing aircraft is to climb him.NCT has to get better at coordination with MRY. We have multiple situations daily at MRY where information is not passed and NCT has not separated aircraft and MRY ends up bailing them out and even situations where NCT will turn aircraft into other aircraft that are talking to MRY. NCT controllers need to be taught basic air traffic control that you cannot hand off an aircraft until all conflicts are resolved; and certainly not hand off a literal deal or safety incident. NCT controllers need to be taught how to sequence; and especially speed sequence; aircraft and be taught basic flight characteristics that aircraft have to slow down to land and the trailing aircraft cannot keep boring down on them at ridiculous closure rates. This is a daily occurrence at MRY and it needs to stop. NCT controllers and Ops Managers need to be taught the rules of tower applied visual separation and when it can be applied; and how to do it. Tower has to actually have aircraft in sight and actually be talking to at least one of them and aircraft are on visual approaches. NCT needs to realize VFR aircraft have to be separated and sequenced as well from IFR aircraft in Class C airspace; as this is also a daily occurrence that MRY ends up bailing NCT out of busted separation. MRY will be sending out more and more [reports] now that this incident with Aircraft X and Aircraft Y narrowly avoided a disaster until NCT does their job of actually sequencing the aircraft they are tasked to. If they cannot handle their responsibility anymore; I highly; highly and am very serious when I suggest the TRACON should be returned back to MRY as better handling would certainly result; since NCT for years has been extremely lacking in their handling of Seca/Fremont airspace that used to be here at MRY as a Tower/TRACON.