General Physics 2 Final Exam

Materials which easily allow the passage of electric current are known as ______

• Insulators

• Conductors

• Dielectrics

• Semi-conductors

A wire of length 2m and another wire of length 5m are made up of the same material and have the same area of cross section, which wire has higher resistance?

• Both have equal resistance

• The 2m wire has higher resistance

• The 5m wire has higher resistance

• The value of resistance cannot be determined from the given data

A wire having an area of cross section = 10sqm and another wire having an area of cross section= 15sqm, have the same length and are made up of the same material. Which wire has more resistance?

• Both have equal resistance

• The 10sqm wire has higher resistance

• The 15sqm wire has higher resistance

• The value of resistance cannot be determined from the given data

Which of the following statements are true with regard to resistance?

• Resistance is directly proportional to a length of the wire

• Resistance is directly proportional to an area of cross section of the wire

• Resistance is inversely proportional to the length of the wire

• Resistance is inversely proportional to the resistivity of the wire

A wire has the same resistance as the one given in the figure. Calculate its resistivity if the length of the wire is 10m and its area of cross section is 2m².

• 16 ohm-metre

• 8 ohm-metre

• 16 kilo ohm-metre

• 8 kilo ohm-metre

Which, among the following is a unit for resistivity?

• ohm/metre

• ohm/metre2

• ohm-metre

• ohm-metre2

Calculate the ratio of the resistivity of 2 wires having the same length and same resistance with area of cross section 2m² and 5m² respectively.

• 5:7

• 2:7

• 2:5

• 7:5

The reciprocal of resistivity is________

• Conductance

• Resistance

• Conductivity

• Impedance

Resistivity of silver rod of length L and area A is 1.5× 10^-8 Ωm. Its conductivity is ___

• 55 x 10⁸ / ohm-meters

• 67 x 10⁸ / ohm-meters

• 6.7 x 10⁶ / ohm-meters

• 67 x 10⁶ / ohm-meters

Constantan wire of length 2 m and area of cross-section 1 mm² has resistivity 49×10^-8 Ω.m. If it carries current of 20 A, the potential difference across the wire is ___

• 20 V

• 40 V

• 60 V

• 80 V