The theodolite is a precision measuring device used to measure horizontal and vertical angles. It works with a combination of: (1) optical plummets, which is used to ensure that it is placed exactly vertical above; (2) internal spirit, which ensures that it is levelled to the horizon; and (3) graduated circles, one vertical and one horizontal, which is used to measure actual angles. The mounted telescope can swivel horizontally and vertically. If this is adjusted correctly, accurate measurements can be obtained.
the answer is b) magnetic current
Answer:
speed of light simulating traveling at the speed of light. Speed of light, speed at which light waves propagate through different materials. In particular, the value for the speed of light in a vacuum is now defined as exactly 299,792,458 metres per second
The speed of sound is the distance travelled per unit of time by a sound wave as it propagates through an elastic medium
Volume by Displacement. The displacement method (submersion, or dunking method) can be used to accurately measure the volume of the human body and other oddly shaped objects by measuring the volume of fluid displaced when the object is submerged.
The following precautions should be taken very observantly:-
The line of sight must be perpendicular to measuring scale to avoid parallax error. Formation of bubbles inside the cylinder should be completely avoided. Any bubbles within leads to wrong measurements.