If a house is bought before marriage and then, after marriage, husband is placed on deed is he entitled to any part of house?

The fact you put your husband's name on your deed will more than likely mean you will have to buy him out (his interest), whatever that may be.  It all depends on how long you owned the home by yourself and how long you lived there as husband and wife.  In New Jersey, as soon as you get married and reside in a home as husband and wife, it does not matter if either the husband or the wife owned the home prior to the marriage, the non-owner will automatically be entitled to some % of the home by virtue of the marriage.  Whether it is 1% or 50%, you will most likely have to pay your husband something, particularly since you need him to sign a deed to get his name off of the house.

To follow up on the previous answers; the issue you face is one the courts call conversion. When one party owns a home prior to the marriage but during the marriage transfers title to both parties, the transfer is considered to be a gift which then transforms the property into a marital asset subject to equitable distribution. It is important to note that even though the case law consistently holds that a premaritally owned residence is converted into an asset subject to equitable distribution when the title is placed in joint names, it does not necessarily follow that the value or the equity of the home will be equally divided by the spouses. If the marriage is a short one, then the spouse who owned the home before the marriage will receive a credit for his/her contribution. However, the longer the duration of the marriage, then it is less likely that the spouse who owned the home before the marriage will receive any contribution credit

Not necessarily.  New Jersey is an "equitable distribution" state, which means marital property isn't automatically divided 50-50 as in community property states.  The court will look at all of the assets and debts, and each party's contribution to those assets and debts, in deciding what is fair.  Your marital lifestyle, and the income and ability of each of you to maintain that lifestyle after divorce, and any child support and alimony decisions are all interconnected.

When you put your husband's name on the deed, that might have effected a gift to him, of an interest in the house;  if your husband's name is on the current mortgage, that would explain it, but it would also create a separate issue unless you could refinance on your own.  You need to talk to a good divorce lawyer, who can look at the whole picture in detail and give you a better idea of what you can expect.