Hello Dipanshu,
I am also preparing for PMP and I feel change log is created first time in "Direct and Manage project work" process where Change request is output.
During this processes, issues arise which may spur proposed changes. The issues are first recorded in the issue log. If after review of the issue log it is determined a change request is required
then the change request is logged in the change log, and the change request goes through the Perform Integrated change control process. Change requests may modify project policies or procedures, project
or product scope, project cost or budget, project schedule, or quality of the project or product results. The project manager should document all issues in the issue log and all change requests in the change log.
Planned risk is not updated in issue log. Issues are something that arise during project and moreover issue log is not a output of any process in Project Risk Management. Prepcast videos in risk management has a good explanation between a risk and a issue.
**Can someone check my explanation here** ??