Scrum questions

1. Can a scrum master handle multiple teams?

Does the Scrum Guide rule this out?

What are your thoughts about whether such a thing could be done well. What constraints and considerations might there be?

2. Can two different boards be used in a single sprint cycle in Jira for tracking the sprint progress for eg: Kanban and Scrum 

The Developers on the Scrum Team ought to be able to monitor their own progress towards their commitments, including the Sprint Goal. Would they find two different boards useful?

1. From my experience this depends on the maturity of the Scrum Master and the Scrum Team.  That is like asking if a Software Engineering Manager can handle multiple teams or if a football coach can handle two teams.  There is no specific answer. 

2. Why would you want two different boards if there is only one team?  This sounds like there might be sub-teams that want to work differently.  I have never seen a single team be effective when trying to use multiple techniques at the same time.  But a Scrum Team is self-organizing so I wouldn't/haven't told teams that they can't.  But the usually decide on their own that it was not a good idea.

1. Can a scrum master handle multiple teams?

Like the others mentioned, this very much depends on the experience and maturity of the Scrum Master and the Scrum Team. If the Scrum Teams need a lot of hands-on teaching and coaching, the Scrum Master will need to spend more time with that team, probably doing more active facilitation of the events. As the team matures and gets experienced, they'd be able to do more on their own without active Scrum Master involvement. However, even with a more mature team, a less experienced Scrum Master may not be able to balance the time to work with everyone as individuals or in groups for multiple teams.

At most, I'd suggest that even an experienced Scrum Master would be able to work with up to 4 teams if the teams were operating in a scaled (such as LeSS or Nexus) setting and working on the same product in the same context. Anything more would probably be stretching the Scrum Master too far.

2. Can two different boards be used in a single sprint cycle in Jira for tracking the sprint progress for eg: Kanban and Scrum 

This isn't so much of a Scrum question as a Jira question. Technically, it's possible. Each Scrum board in Jira would have its own Sprints and Kanban boards wouldn't be related to Sprints at all. However, you can set up a different board to give you a different view of the data. I'm just not sure how valuable this would be at all for a single team. I've done similar things to create a view across multiple teams for a product-level perspective, but I can't see the use for one team within a Sprint.

2. Can two different boards be used in a single sprint cycle in Jira for tracking the sprint progress for eg: Kanban and Scrum 

You could look into implementing Scrum with Kanban.  This site has lots of information around PSK which should help the scrum team decide if this is what they wish to try or not.