Recent questions in Current Electricity

Two electric bulbs A and B are marked 220V , 40W and 220V 60W respectively. Which one has a higher resistance?
Answer : **The 40W bulb (Bulb A) has a higher resistance.** Here's the detailed explanation of why: ### The Relationship The relationship between Power (P), Voltage (V), and Resistance (R) is given by ... to get more water through a pipe; you need a wider pipe (less resistance) to increase the flow rate....

Two wires A and B are of the same metal and of same length have their areas of cross section in the ratio 2:1 if the same potential difference is applied across each wire in turn, what will be the ratio of current flowing in A & B ?
Answer : The ratio of the current flowing in wire A to wire B is **2:1**. --- ### Detailed Explanation Let's break down the problem using the relevant physics principles. #### 1. List the Given ... resistance, which is wire A. Our result confirms this: the current in A is twice the current in B....

Name any one material having a small value of temperature coefficient of resistance. Write one use of this material?
Answer : **Material:** **Manganin** (an alloy of copper, manganese, and nickel) **Use:** Due to its very low temperature coefficient of resistance, it is used to make ** ... for electrical measuring instruments like ammeters and Wheatstone bridges, where a stable and predictable resistance is essential....

If a wire is stretched to double its length. What will be its new resistivity?
Answer : The short answer is: **The new resistivity will be exactly the same.** --- ### The Detailed Explanation #### What is Resistivity? **Resistivity (ρ)** is an **intrinsic property** of a material. This ... 2) and area is halved (factor of 1/2). | Becomes **four times** the original resistance. |...

Draw the graph showing the variation of conductivity with temperature for a metallic conductor?
Answer : The conductivity for a metallic conductor decreases with the increase in temperature. ![][1] [1]: https://electrical-engineering.app/?qa=blob&qa_blobid=10491891827766109637 ### Explanation: The Physics Behind the Graph To understand this ... | **Low** |...

State one condition for maximum current to be drawn from the cell?
Answer : For maximum current to be drawn from a cell, the **external resistance in the circuit should be zero**. This condition is also known as a **short circuit**. **Explanation:** The current (I) drawn from a cell ... possible value is 0. When R = 0, the current is at its maximum value, I_max = E / r....

If potential difference V applied across a conductor is increased to 2V , how will the drift velocity of the electron change?
Answer : ### Short Answer If the potential difference V applied across a conductor is increased to 2V, the **drift velocity of the electrons will also double**. ### Detailed Explanation Let's ... the electric field, which doubles the force on the electrons, which doubles their average drift velocity....

If the temperature of a good conductor decreases, how does the relaxation time of electrons in the conductor change?
Answer : ### The Short Answer If the temperature of a good conductor decreases, the **relaxation time of electrons increases**. --- ### The Detailed Explanation To understand why, let's break ... **. This is why good conductors become even better conductors (less resistive) at lower temperatures....