Juniper exams are becoming very popular with the advancement of Internet. JNCIA, a basic Juniper certification, tests candidates in fundamental networking technologies such as subnets, routing, switching, etc. using Juniper routers and switches.
CertExams.com provides Juniper Exam Simulator for JNCIA (http://www.certexams.com/JuniperSim/exam-details.htm) that consists of 250+ questions with answers and flash card explanations. Check it out.
Related links:
JNCIA blog (http://junipernetsim.blogspot.in/)