Three copper wires have their lengths in the ratio 5:3:1 and their masses are in the ratio 1:3:5. Their electrical resistance will be in the ratio of :
1. 5:3:1
2. 1:3:5
3. 125:15:1
4. 1:15:125
The current \(I\) as shown in the circuit will be:
1. | \(10~\text{A}\) | 2. | \(\dfrac{20}{3}~\text{A}\) |
3. | \(\dfrac{2}{3}~\text{A}\) | 4. | \(\dfrac{5}{3}~\text{A}\) |
1. | \(28\) C | 2. | \(30.5\) C |
3. | \(8\) C | 4. | \(82\) C |
When the length and area of cross-section both are doubled, then its resistance :
1. Will become half
2. Will be doubled
3. Will remain the same
4. Will become four times
1. | proportional to \(T\). | 2. | proportional to\(\sqrt{T} \) |
3. | zero. | 4. | finite but independent of temperature. |
An electric wire of length ‘I’ and area of cross-section a has a resistance R ohms. Another wire of the same material having the same length and area of cross-section 4a has a resistance of :
1. 4R
2. R/4
3. R/16
4. 16R
A wire of radius r has resistance R. If it is stretched to a radius of , its resistance becomes
1.
2.
3.
4.
Express which of the following setups can be used to verify Ohm’s law
1. | |
2. | |
3. | |
4. |
What is the resistance of a carbon resistance which has bands of colours brown, black and brown
1. 100 Ω
2. 1000 Ω
3. 10 Ω
4. 1 Ω
The following four wires are made of the same material and are at the same temperature. Which one of them has highest electrical resistance :
1. Length = 50 cm, diameter = 0.5 mm
2. Length = 100 cm, diameter = 1 mm
3. Length = 200 cm, diameter = 2 mm
4. Length = 300 cm, diameter = 3 mm