Advertisements
Advertisements
Question
Two copper wires are of the same length, but one is thicker than the other. Which wire will have more resistance?
Advertisements
Solution 1
We know that,
R = `ρl/A`
Where, ρ = specific resistance
L = length of wire
A = area of cross-section
let the area of the cross-section of the wires be A1 & A2. It is said that one is thicker than the other.
So A1 > A2
When the length of the wire is given to be the same then we can see that `R prop 1/A`.
So, the wire with less area of the cross-section will have more resistance.
Solution 2
The area of the cross-section has an inverse relationship to resistance, so a thinner wire will have more resistance.
APPEARS IN
RELATED QUESTIONS
Name three factors on which resistance of a given wire depends and state how is it affected by the factors stated by you.
Exercise.
The values of current (I) flowing through a resistor for various potential differences V across the resistor are given below. What is the value of resistor?
| I (ampere) | 0.5 | 1.0 | 2.0 | 3.0 | 4.0 |
| V (volt) | 1.6 | 3.4 | 6.7 | 10.2 | 13.2 |
An electric bulb is rated ‘240 V, 100 W’.
- What information can you get from the above statement?
- What will happen if this bulb is connected across 220 V?
- Calculate the resistance of the bulb.
- Also find the energy consumed by the bulb in 10 minutes.
The resistance of a straight conductor is independent of ______.
Two conductors of resistance 2 R and R are connected in series in a battery circuit. The ratio of heat developed In them is ______.
Resistors are connected in series if the resistance of the electric circuit is to be ______.
______ is the only non-metal that is a good conductor of electricity.
A rheostat is also known as fixed resistance.
|
5 bulbs are connected in series in a room. One bulb is fused. It is removed and remaining 4 bulbs are again connected in series to the same circuit. What will be the effect on the following physical quantities? (Increases, Decreases, Remain Same). |
- Resistance
- Intensity of light
Observe the given circuit diagram and answer the questions that follow:
- Calculate the resistance of the circuit when the key K completes the circuit.
- Calculate the current through 3Ω resistance when the circuit is complete.
