逼迫 sounds stronger than 强迫. If someone 强迫 you to do something, you feel the pressure to do it, but there might be a slight chance that you can get out of it. If someone 逼迫 you to do something, you kind of have to do it because that person might have something on hand that can threaten you to do so, such as your life, your secret, for example, a mugger sticks a knife to you neck to force you to give out the money. In this case, he/she uses your life to threaten you. That's my understanding about the two words. Hope it helps.

"Forced" would be a more appropriate translation for 强迫. 逼迫 should mean "oppressed' in English. In general, 强迫 is used when the action was done on a person to person basis. Eg: 他强迫我签了那份合同 - He forced me to sign the contract Example for 逼迫 would be (i) 人民在政府的逼迫下，不得已离开家园 - People have left their home under the oppression from the government.

逼迫更强烈一些，都有让人做不爱做的事的意思。 举例： 妈妈总是【强迫】我吃不喜欢吃的东西。 地主【逼迫】她晚上也工作，不能休息。