Verify the design of the chair
verify of which material it is made
verify the height of the chair
verify the strongness of the chair
verify the color of the chair

and so on....

Hi, Some test cases for the chair could be..
1) Check all the joints of the chair.
2) Check the color of the chair.
3) Check all the legs of the chair must be equal.
4) Check whether the chair is strong enough or not,means how  
   much load can we put into it.
5) Check weather the built of the chair is comfortable in 
   sitting or not.
6) If its a revolving chair then verify its machinery is 
   working properly or not.
7) Check all the handles of the chair are strong enough or not.

Plz correct me if i m wrong...
Regards 
nitin9360@gmail.com

Thanx for the answers.

Ask the interviewer for the requirements specification 
document then you can tell the possible test cases.

for such type of pencil,chair,table,pen,questions. we must
divide the test case into usability, functional,
non-functional so it would be easy to formulate an answer