Resistance is a measure of the opposition to current flowing in an electric circuit. It is measured in ohm, symbolised by Greek word omega (Ω). But the quantity more basic than resistance is resistivity. It will be independent of the geometry of the conductor. It depends only on the nature of material of the conductor and temperature of the conductor.
It has been found that the resistance R of a conductor depends upon
1. Directly proportional to the Length of the conductor
R ∝ l(length )
2. Inversely proportional to Area of cross section of conductor
R ∝ 1 / A (Area)
R = ρ L/ A
Where ρ is known as specific resistance or electrical resistivity of the
material of conductor
Q1 Resistance of a conductor depends directly upon
- Pressure
- area
- length
- relaxation time
- length
Q2 With increase in area of cross section ,the resistance of the conductor
- Increases
- decrease
- remain same
- None of these
- decrease
Q3 Resistivity of a conductor varies inversely with
- Nature of material
- area
- length
- none of above
- area
Q4 Resistivity of semiconductors
- Decrease with temperature
- increase with temperature
- no change
- None of the above
- Decrease with temperature
Q5 Resistivity of conductors
- Decrease with temperature
- increase with temperature
- no change
- None of the above
- increase with temperature
Q6 Electrical resistivity is also known as ..............resistance
- Small resistance
- Large resistance
- shunt
- Specific
- Specific
Q7 Resistance has SI unit as
- Ohm meter
- ohm
- mho
- none of these
- ohm
Q8 Resistivity has SI unit as
- Ohm meter
- ohm
- mho
- none of these
- Ohm meter
Q9 Resistivity is independent of temperature (True/False)
- True
- false
- False
Q10 Resistance depends upon length of conductor (T\F)
- True
- false
- True
