about 1/3 of a neutron star
The material sucked in to a black hole becomes part of the black hole - that is, a black hole crushes matter to an nearly no size, at all.
Any matter that enters the black hole will be destroyed. Also, it will increase the black hole's size.
A black hole can definitely get to the size of a planet. The width of the largest known supermassive black hole is thought to be over ten times the size of the entire orbit of Neptune around our Sun.
No.
yes and no depends on size of hole :]
The size of a black hole, as defined by the size of the event horizon, depends on the mass of the black hole and its electrical charge. The diameter of the event horizon is directly proportional to the black hole's mass. Adding electrical charge decreases the size of the event horizon.
You would have a black hole the size of the combined mass of the two black holes.
There isn't one. It depends on how much matter the collapsed star (black hole) has gathered.
Yes. Intermediate-mass blackhole is a medium size black hole. Scientists have found stellar black holes and supermassive black holes but there is no prove that Intermediate-mass black type of black holes exist. My opinion is that they do exist because when a black hole is becoming a black hole supermassiveblack hole it will need to go though this stage of intermediate-mass black hole.
yes
Depends!!!A white dwarf created from a star the same size as our Sun will only be the size of our Earth.A supermassive black hole can have a diameter of 150 million kilometers (Same distance from the Earth to the Sun).However a stellar black hole can only be 30 kilometers in diameter.There is no minimum size for a black hole, so one "could" be as small as 0.1mm
The size of a black hole is a meaningless quantity. The black hole itself, meaning the matter contained within, is infinitely small. However black holes can be defined by their schwartzchild radius which is the size of the event horizon. Look the equation for it up somewhere.