To find the Young modulus of a wire, a number of readings are recorded. In which row is it not possible to make the measurement directly using the apparatus given?
- Ameasurement: area of cross-section of wire; apparatus: micrometer screw gauge
- Bmeasurement: extension of wire; apparatus: vernier scale
- Cmeasurement: mass of load applied to wire; apparatus: electronic balance
- Dmeasurement: original length of wire; apparatus: metre rule