The value of η 2 varies between 0 and 1.

The value of the variable η 2 ranges between 0 and 1 as it represents the efficiency of the solar cell, which is a ratio of the useful electrical output to the total energy input. A ratio cannot be negative, and it cannot exceed 1 or 100%. Therefore, the answer is true.

The value of η 2 varies between 0 and 1.

The value of the variable η 2 ranges between 0 and 1 as it represents the efficiency of the solar cell, which is a ratio of the useful electrical output to the total energy input. A ratio cannot be negative, and it cannot exceed 1 or 100%. Therefore, the answer is true.