Conformations of ethane derivatives: dihedral angle and stability

This type of question, asked 4 times: 2021 Paper 16, 2021 Paper 17, 25 Jun 2022, 25 Jan 2023. All 4 questions below, oldest first.

Try each one first, then open its answer.

Question 1
2021 Paper 16
28 $Staggered and eclipsed form of ethane are:$
Tap an option to check your answer.
Question 2
2021 Paper 17
58 $The dihedral angle in staggered form of Newman projection of 1,1,1-trichloroethane is ____ degrees. (Round off to the nearest integer)$
Question 3
25 Jun 2022
42 $In the following structures, which one is having staggered conformation with maximum dihedral angle?$
Tap an option to check your answer.
Question 4
25 Jan 2023
34 $Which of the following conformations will be the most stable?$
Tap an option to check your answer.

Question 1