Concept: According to Ohm's Law, the flow of electric current through a conductor is directly proportional to the potential difference across it, provided physical conditions (like temperature, pressure, volume etc.) remains same.
v = ir
or, r = v / i
Here, current (i) is measured by Ammeter which should be connected in series of any electrical circuit.
voltage (v) is measured by Voltmeter which should be connected parallel to the external resistance (r).
In the given experiment, the first arrangement of the circuit will show the smallest error because the voltmeter is connected exactly parallel to the external resistance.
In the second arrangement, the voltmeter is connected across external resistance (r) and Ammeter (A) and in this case, the voltmeter will not measure the exact potential drop across the external resistance (r). So, there would be more error.
It makes calculations with very large and small numbers easier.
Scientific notation is a system used in order to It makes calculations with very large and small numbers easier. It is useful as it allows very large number that would take a lot of space to write otherwise, and it allows them to be calculated easier. 
for example is a incredible large number, but written in this form is immediately understandable and useful for calculation.
The earths crust starts the beginging of growth of land and plants while the earths mantle is deeper and has no life living on top of it
Answer: Vibrating
Explanation:
Sound is produced when an object vibrates. The sound vibrations cause waves of pressure that travel through a medium, such as air, water, wood or metal. Sound is a form of mechanical energy.
Kepler's second law of planetary motion says that the imaginary line
from the Sun to the planet sweeps out equal areas in equal periods
of time.
It's just as true of comets, asteroids, dwarfs, coasting space probes ...
anything in the solar system that's coasting in gravity, and not firing engines.
That's why a comet moves so fast when it gets near the Sun.
