Askiitians Tutor Team
Last Activity: 5 Months ago
a) The unit of resistance is the ohm, symbolized by the Greek letter Ω. One ohm is defined as the amount of resistance that will allow one ampere (A) of current to flow when a voltage of one volt (V) is applied across it. Mathematically, this can be expressed as:
1 ohm (Ω) = 1 volt (V) / 1 ampere (A)
b) As the conductor is made thinner (i.e., its cross-sectional area decreases), its resistance increases. This relationship is described by the formula for resistance:
R = ρ * (L / A)
Where:
R is the resistance (in ohms, Ω)
ρ (rho) is the resistivity of the material (a constant property of the material)
L is the length of the conductor
A is the cross-sectional area of the conductor
Since resistance is directly proportional to the length (L) of the conductor and inversely proportional to the cross-sectional area (A), decreasing the cross-sectional area by making the conductor thinner will result in an increase in resistance.
c) If the resistance of a circuit is doubled while keeping the potential difference (voltage) constant, Ohm's Law can be used to determine how the current changes. Ohm's Law states:
V = I * R
Where:
V is the potential difference (voltage)
I is the current
R is the resistance
If the resistance is doubled (2R), and the potential difference (V) remains constant, we can rearrange Ohm's Law to solve for the new current (I'):
V = I' * (2R)
Now, isolate I' by dividing both sides by 2R:
I' = V / (2R)
So, when the resistance is doubled, the current is reduced to half of its original value, assuming the potential difference remains the same.