While teaching the correct method of using a spring balance, a teacher listed the following steps to be followed: A. Note the zero error. B. Note the position of the pointer on the graduated scale. C. Record the least count of the spring balance. D. Calculate the actual reading. What is the correct sequence of steps to be followed?

Students measuring Young's modulus of a wire record inconsistent elongation. Which of the following represents the best experiential learning approach to address this issue?

Assertion A: If in five complete rotations of the circular scale, the distance travelled on the main scale of a screw gauge is 5 mm and there are 50 total divisions on the circular scale, then the least count is 0.002 cm. Reason R: Least Count = PitchTotal divisions on circular scale. In the light of the above statements, choose the most appropriate answer from the options given below: