Recent questions without an upvoted answer

A steady current flow in a metallic conductor of non-uniform crosssection. Which of these quantities is constant along the conductor: current, current density, electric field, drift speed?
Answer : Here is a detailed explanation for each quantity: ### 1. Current (I) * **Why it's constant:** The term "steady current" implies that the rate of flow of charge ($I = dQ/dt$) is constant. Due to the ... ($v_d$)** | Not Constant | $v_d = I/(nAe)$. Since A is not constant, $v_d$ is not constant. |...

Six lead-acid type of secondary cells each of emf 2.0 V and internal resistance 0.015 Ohm are joined in series to provide a supply to a resistance of 8.5 Ohm . What is the current drawn from the supply and its terminal voltage?
Answer : ### Given Data: * Number of cells, **n = 6** * EMF of each cell, **E_cell = 2.0 V** * Internal resistance of each cell, **r_cell = 0.015 Ω** * External resistance (load), **R = 8.5 Ω ... The current drawn from the supply is **1.40 A**. * The terminal voltage of the supply is **11.9 V**....

A storage battery of emf 8.0 V and internal resistance 0.5 Ohm is being charged by a 120 V DC supply using a series resistor of 15.5 Ohm . What is the terminal voltage of the battery during charging? What is the purpose of having a series resistor in the charging circuit?
Answer : ### Given Data: * Electromotive force (emf) of the battery, $E = 8.0 \text{ V}$ * Internal resistance of the battery, $r = 0.5 \text{ } \Omega$ * DC supply voltage, $V_{supply} = ... to a much safer and more manageable **7.0 A**, protecting both the battery and the power supply from damage....

A silver wire has a resistance of 2.1 Ohm at 27.5 degree C , and a resistance of 2.7 Ohm at 100 degree C . Determine the temperature coefficient of resistivity of silver.
Answer : ### 1. Understand the Principle The relationship between resistance and temperature for most metals (like silver) over a moderate temperature range is approximately linear and can be described by the formula: $R_2 = ... 00394 °C⁻¹** Alternatively, in scientific notation: **α = 3.94 x 10⁻³ °C⁻¹**...

Three resistors 1 Ohm , 2 Ohm and 3 Ohm are combined in series. What is the total resistance of the combination?
Answer : When resistors are combined in series, the total resistance is the sum of the individual resistances. The formula is: R_total = R1 + R2 + R3 Given the values: * R1 = 1 Ω * R2 = 2 Ω * R3 = 3 Ω ... = 1 Ω + 2 Ω + 3 Ω = 6 Ω So, the total resistance of the combination is **6 Ohms**....

A battery of emf 10 V and internal resistance 3 Ohm is connected to a resistor. If the current in the circuit is 0.5 A, what is the resistance of the resistor? What is the terminal voltage of the battery when the circuit is closed?
Answer : ### Given Information: * **EMF of the battery (E):** 10 V * **Internal resistance (r):** 3 Ω * **Current in the circuit (I):** 0.5 A --- ### 1. What is the resistance of the ... text{V}$ Both methods give the same result. **Answer:** The terminal voltage of the battery is **8.5 V**....

Define emf. of a cell? On what factors does it depend?
Answer : ### Definition of EMF (Electromotive Force) The **EMF (Electromotive Force)** of a cell is defined as the maximum potential difference between its two terminals when no current is being drawn ... *, not its EMF. A larger distance increases the path ions must travel, increasing internal resistance....

Three identical cells, each of emf. 2V and unknown internal resistance are connected in parallel. This combination is connected to a 5 ohm resistor. If the terminal voltage across the cell is 1.5 volt. What is the internal resistance of each cell? Hence define the internal resistance of a cell?
Answer : ### Part 1: Calculating the Internal Resistance Here's how we can find the internal resistance of each cell. **Given Data:** * Electromotive force (EMF) of each cell, E = 2 V * Number of identical cells ... . * **I** is the current flowing from the cell. * **r** is the internal resistance....

A cylindrical wire is stretched to increase its length by 10% calculate the percentage increase in resistance?
Answer : The percentage increase in resistance is **21%**. Here is the step-by-step calculation and explanation: ### The Key Concepts 1. **Resistance Formula:** The resistance (R) of a wire is given by: $R = \ ... R_1}{R_1} \times 100\%$ $\text{Percentage Increase} = 0.21 \times 100\% = \bf{21\%}$...

Obtain ohm’s law from the expression for electrical conductivity.
Answer : We can derive the familiar form of Ohm's Law ($V=IR$) by starting with the fundamental expression for electrical conductivity ($\sigma$). This derivation beautifully connects the microscopic behavior of ... total **current ($I$)** flowing through it, successfully obtaining Ohm's Law, $V=IR$....