From the log statement, resource named "componentResource" that you are injecting in the model is null. (which is the starting point in the getFaqQuestionAnswerArray() method) because of this it a NPE on getFaqQuestionAnswerArray() method from the test class.
Could you please share your
Mock JSON file(pdp.json) and
Screenshot of component node structure from CRXDE as available under content path (faqcomponent available under the respective /content path say /content/xyz/page/jcr:content/root/responsivegrid/faqcomponent)