Units and Measurements Quiz

Study Notes

Fundamental Units: The fundamental units in the International System of Units (SI) are length (meter, m), mass (kilogram, kg), time (second, s), electric current (ampere, A), thermodynamic temperature (kelvin, K), amount of substance (mole, mol), and luminous intensity (candela, cd).
Derived Units: Derived units are combinations of fundamental units. Examples include speed (m/s), acceleration (m/s²), force (kg⋅m/s² or Newton, N), and energy (kg⋅m²/s² or Joule, J).
Significant Figures: Significant figures represent the degree of accuracy in a measurement. Rules for determining significant figures include counting all non-zero digits, captive zeros, and trailing zeros in a number containing a decimal point.
Errors in Measurement: Errors arise from instrument limitations, human error, and environmental factors. Errors are categorized into systematic and random errors. Systematic errors are consistent, repeatable inaccuracies, while random errors fluctuate unpredictably.
Accuracy and Precision: Accuracy is the closeness of a measured value to the true value; precision is the reproducibility of a measurement. High precision does not guarantee accuracy.

Electric Charge: Matter consists of particles with electric charge. The fundamental unit of charge is the elementary charge (e), approximately equal to 1.602 x 10⁻¹⁹ Coulombs. Charges can be positive or negative. Like charges repel, opposite charges attract.
Coulomb's Law: Coulomb's law describes the electrostatic force between two point charges. The force is directly proportional to the product of the charges and inversely proportional to the square of the distance between them.
Electric Field: An electric field surrounds any electrically charged object. The electric field is a vector quantity, representing the force a unit positive charge would experience at a given point.
Electric Potential: Electric potential is the work needed to move a unit positive charge from a reference point to a specific point within the electric field.
Capacitance: Capacitance is the ability of a system to store electrical energy. A capacitor is a device for storing electrical energy; it consists of two conductors separated by an insulator.
Electric Potential Energy: The work to move a charge in an electric field from one location to another depends on the charge magnitudes and the distance between them.