Question
Which is dimensionless
✓
Answer
Hint: If two quantity have same dimension then their ratio will be dimensionless.
Explanation: $A$ dimensionless quantity means the quantity which has no physical dimension or has a dimension one, they are also referred to as scalar quantities. They are often obtained as the ratio of two or more quantities. Since the dimension of work and energy is the same, i.e., $ML ^2 T ^{-2}$, when we take their ratio both the dimensions will cancel out and the result will be a dimensionless quantity.
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