Static Electricity and Resistance OZ 9B

Which two changes to a metal wire both increase resistance?

• A Decreasing its length and increasing its temperature.

• B Increasing its length and decreasing its temperature

• C Decreasing its thickness and increasing its temperature.

• D Increasing its thickness and decreasing its temperature.

A metal wire of length 100cm and a cross-sectional area of 0.20 mm2 has a resistance of 8.0 ohms. What is the resistance of a wire of the same metal of length 50 cm and cross-sectional area of 0.40mm2?

• A 2.0 Ohms

• B 8.0 Ohms

• C 16 Ohms

• D 32 Ohms

Two wires X and Y are made from the same metal and have the same resistance. Which row identifies a possible pair of values for X and Y?

• A

• B

• C

• D

Which diagram shows the current-voltage (I-V) characteristic for a filament lamp?

• A

• B

• C

• D

1. A metal sphere is charged by induction. There are four stages W, X, Y, Z in this process. In which order are they carried out?

• A W then X then Y then Z

• B W then X then Z then Y

• C Z then W then X then Y

• D X then Z then W then Y

The diagrams represent four copper wires.

Which wire has the greatest resistance?

• A

• B

• C

• D

A student used a length of wire as a resistor. He discovers that the resistance of the wire is too small. To be certain of making a resistor of higher value, he should use a piece of wire that is

• A Longer and Thicker

• B Longer and Thinner

• C Shorter and Thicker

• D Shorter and thinner

When the thermistor in the circuit below is heated, the current in the lamp increases. Why does this happen?

• A The resistance of the lamp decreases.

• B The resistance of the lamp increases.

• C The resistance of the thermistor decreases.

• D The resistance of the thermistor increases.

The diagram shows a circuit used to find the resistance of lamp L. Blocks P, Q, and R represent the different components used. Which is a correct possible choice of components to use for P, Q, and R.

• P Ammeter Q Variable resistor R Voltmeter

• P Variable resistor Q Voltmeter R Ammeter

• P Voltmeter Q Ammeter R Variable Resistor

• P Voltmeter Q Variable resistor R Ammeter

Which circuit should be used to find the resistance of a lamp?

• A

• B

• C

• D