No , the meaning of these sentence are not similar first two sentences means- is miss zhang at home? , is this miss zhang's home? 2. meaning of these sentences are as follow- ( here your first sentence is wrong you should use 才 instead of 就 because class time is fixed and he came late， so your correct sentence is ) 八点上课，他八点半才来了-- classs began at 8 o'clock but he came at 8:30. 八点上课，他八点十分才来-- class began at 8 o'clock, he came at 8:10. 昨天我去北京吃饭，八点坐车，八点半就到了。yesterday i went to beijing and had a meal, got on bus at 8 o'clock , and reached at 8 :30. i think in last sentence you have made a mistake- you should write like this--今天我去诶经吃饭，八点坐车，八点半才到。 Today i went to beijing , got bus at 8 o'clock but reached late at 8:30.( because here you are using 才 so it shows some late and you took bus at 8 o'clock and reached also at 8 o'clock so here i added some more minutes to reach ） hope you understand well now!!

张老师在家吗？ Is teacher Zhang at home? 张老师家吗？ IS this the home of teacher Zhang? the above two sentences are different. 八点上课，他八点半就来了。八点上课，他八点十分才来。 i find one mistake in the first sentence. the right one shoud be : 八点上课，他八点半才来。 because lessons begin at 8 o'clock, he comes at 8:30. so he's late, and we should use 才 not 就来了