RTBC - Electrical Physics Questions and Answers Already Passed

RTBC - Electrical Physics Questions and Answers Already Passed What is electric current? Electric current is the flow of electric charge, typically measured in amperes (A). What is the difference between AC and DC current? AC (alternating current) changes direction periodically, while DC (direct current) flows in only one direction. What is the purpose of a resistor in an electrical circuit? A resistor limits the flow of electric current, helping to control voltage and protect components. How does voltage affect an electric circuit? Voltage is the electrical potential difference that drives current through a circuit. Higher voltage increases the current if resistance remains constant. What is Ohm’s Law? 2 Ohm’s Law states that voltage (V) equals current (I) multiplied by resistance (R), written as V = IR. What happens to current if resistance increases while voltage remains the same? The current decreases, as resistance opposes the flow of electric charge. Why are conductors used in electrical circuits? Conductors allow electric current to flow easily due to their low resistance, typically made of materials like copper or aluminum. What is the function of an insulator in an electrical circuit? An insulator prevents the flow of electric current, protecting users and components from electrical hazards. How does a capacitor work in an electrical circuit? A capacitor stores and releases electrical energy, often used to smooth voltage fluctuations or provide temporary power. What is electrical power, and how is it calculated? 3 Electrical power is the rate at which electrical energy is used or transferred, calculated as P = VI (power = voltage × current). What is the role of a transformer in an electrical system? A transformer changes the voltage of an AC supply, either increasing (step-up) or decreasing (step-down) voltage for different applications. Why are fuses used in electrical circuits? Fuses protect circuits from excessive current by melting and breaking the circuit when the current exceeds a safe level. What is electromagnetic induction? Electromagnetic induction is the process of generating an electric current by changing the magnetic field around a conductor. How does a diode function in a circuit? A diode allows current to flow in only one direction, preventing reverse current flow and protecting circuit components.