Experimental Determination of Resistance and Electrical Energy Quiz

Why is it important to set the rheostat to maximum resistance at the start of an experiment?

• To get the highest possible current reading
• To protect the circuit components from excessive current
• To ensure the most accurate voltage readings
• To make the experiment run faster

When plotting V vs I for a metal wire at constant temperature, what does a straight line through the origin indicate?

• The wire has zero resistance
• The resistance varies with current
• The resistance is constant (ohmic conductor)
• The wire is superconducting

Why does the V-I graph for a filament lamp curve upward?

• The lamp becomes more efficient
• Resistance increases with temperature
• The wire becomes longer
• Voltage causes the wire to stretch

In the equation E = QV, what does Q represent?

• Quality of the conductor
• Quantum energy level
• Electric charge in Coulombs
• Quantity of voltage

Why should connections be kept clean in electrical experiments?

• To make the equipment look better
• To prevent corrosion damage
• To minimize contact resistance
• To avoid electrical sparks

If power P = VI and V = IR, what is the alternative expression for power?

• P = I²R
• P = I/R
• P = V²/I
• P = IR²

Why is it necessary to allow cooling between readings when measuring resistance?

• To save electricity
• To prevent temperature-induced resistance changes
• To protect the measuring instruments
• To get lower readings

If electric energy E = VIt, and power P = VI, what is the relationship between energy and power?

• E = P/t
• E = Pt
• E = P²t
• E = P+t

What physical quantity is measured in Watts?

• Resistance
• Current
• Energy
• Power

Which equation would you use to calculate the energy transferred if you know the current and resistance?

• E = IR
• E = I²Rt
• E = IR/t
• E = I²/R