Q1: An error of 1% in measuring the head of water over the crest of a triangular notch, produces an error in the discharge which is equal to

ANS:D - 2.5%

The relationship between the error in the head measurement and the resulting error in discharge for a triangular notch can be expressed by empirical formulas derived from experimental data. For a triangular notch, the relationship between the error in head measurement and the resulting error in discharge is approximately 2.5 times the percentage error in head measurement. This relationship is an approximation and may vary slightly depending on the specific characteristics of the notch and the flow regime. Therefore, if there's a 1% error in measuring the head of water over the crest of a triangular notch, the resulting error in discharge would be approximately 1%×2.5=2.5%. Hence, the correct answer is 2.5%.