Hot questions

Is ohm’s law universally applicable for all conducting elements? If not, give examples of elements which do not obey Ohm’s law.
Answer : The answer is no, **Ohm's law is not universally applicable for all conducting elements.** Ohm's law is an empirical rule, not a fundamental law of nature. It accurately describes the ... under stable conditions, but it is far from a universal law for all materials that conduct electricity....

Explain with justification two uses of each of two following as an electrical conductor: (i) Brass (ii) Silver
Answer : ### (i) Brass Brass is an alloy primarily made of copper and zinc. While it is a good electrical conductor, it is not as conductive as pure copper. Its usefulness comes from a ... silver (lowest possible signal loss) while keeping the cost much lower than using a solid silver conductor....

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. |...

State two insulators of following types along with their areas of application: (i) Class A (ii) Class E (iii) Class H
Answer : Here are two examples of insulating materials for each specified class, along with their areas of application. These insulation classes are defined by their maximum allowable operating temperature, ... traction motors (used in trains), which operate under severe thermal and mechanical stress....

Explain the phenomenon of loss of magnetism.
Answer : ### The Short Answer Loss of magnetism, also known as **demagnetization**, is the process where a magnetic material loses its magnetic properties. This happens when the microscopic "mini-magnets" inside the material, ... 's own stray field. | A structure slowly eroding due to wind and rain. |...

A low voltage supply from which one needs high currents must have very low internal resistance. Why?
Answer : ### The Simple Analogy: A Water Pipe Imagine your power supply is a large water tank (representing the voltage) and you need to get a high flow of water (high current) out of a pipe at ... extremely small, this will generate a massive amount of heat, which can damage or destroy the power supply....

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**....

Describe with reasons the failure of porcelain insulators.
Answer : ### **Introduction: The Role of Porcelain Insulators** Porcelain insulators are a critical component in electrical power systems. Their primary functions are twofold: 1. **Electrical Insulation: ... , and maintenance strategies (like insulator washing) to ensure the reliability of the power grid....

State the properties of copper and aluminium which make them good conductors of electricity.
Answer : ### 1. Presence of Delocalized Valence Electrons This is the most fundamental reason. * **What it is:** In metallic bonding, the outermost electrons (valence electrons) of the ... density and lower cost make it a vital material for specific applications like long-distance power transmission....