Skip to main content

Questions from potentiometer

 Potentiometer





Questions from potentiometer


Q1. Why is a potentiometer preferred over a voltmeter for measuring the emf of a cell?

Ans. Potentiometer work on null method, It does not draw any current from the cell thus there there is no potential drop due to the internal resistance of the cell. It measures the potential difference in an open circuit which is equal to the actual EMF of the cell. It is very accurate device.
On the other hand, voltmeter draw small current from the cell for its operation. So it measures terminal potential difference in a closed circuit which is less than EMF of the cell


Q2. The sensitivity of a potentiometer increases with increase in length of its wire. Explain why?

Ans. When the length of the wire increases the fall of potential per unit length of the wire become smaller (i.e potential gradient K= V/L ). Hence even a small potential difference can be measured.


Q3. Sometime the balance point in the potentiometer may not be obtained on the wire explain why?

Ans. When the EMF of the driving cell ,(auxiliary cell ) is less than the EMF of the cell being measured. We do not get balance point any where on the wire of potentiometer.


Q4. In a potentiometer experiment why it is is necessary to use a long wire?

Ans. Longer wire has a small potential gradient K= V/L ) consequently it is more sensitive and hence preferred.



Labels:

Comments

Post a Comment

Thanks for your comments

Read this Article

Climate Change and Los Angeles Wildfires

  Climate Change and Los Angeles Wildfires: A Growing Crisis Wildfires in Los Angeles have become more frequent and destructive, largely driven by climate change. Rising global temperatures, prolonged droughts, and extreme weather events are fueling this escalating problem, posing serious risks to people, property, and the environment. How Climate Change Fuels Los Angeles Wildfires 1. Rising Temperatures Climate change has led to higher temperatures, creating hotter and drier conditions. These extreme conditions dry out vegetation, turning it into flammable fuel for wildfires. 2. Longer Fire Seasons California’s wildfire season now spans almost the entire year. This extended season is caused by earlier snowmelt, reduced rainfall, and prolonged dry spells due to climate change. 3. Drought and Vegetation Stress Persistent droughts in Los Angeles weaken vegetation, making it more susceptible to fires. Climate change exacerbates these droughts, increasing wildfire risks. 4. Extreme Wea...
Post a Comment
Next ⏭️

A organic material manure

 An organic material used as a natural fertilizer to enrich the nutrients of soil and promote plant growth is Manure.  It primarily or mainly consists of animal waste (like cow dung, horse manure, poultry droppings) mixed with bedding materials such as straw or hay. Manure provides essential nutrients like nitrogen, phosphorus, and potassium to the soil, improving its fertility and structure. Types of Manure:__ 1. Green Manure: This type of manure is made by growing and plowing under specific plants (e.g., legumes) to improve soil fertility. 2. Animal Manure: This kind of manure is produced from livestock waste, commonly used in farming. 3. Compost Manure: This kind of manure is made by decomposing organic household and garden waste into nutrient-rich humus. Benefits of Manure are as follows:__ __It enhances structure of soil by improving aeration and drainage. __It provides essential nutrients for plant growth. __It encourages microbial activity in the soil, making nutr...
Post a Comment
Next ⏭️

Indian standard code for civil engineering

What are IS Codes for Civil Engineering? IS codes, also known as Indian Standard codes, are a collection of standards formulated by the Bureau of Indian Standards (BIS) for diverse aspects of civil engineering. These codes offer guidelines, specifications, and safety prerequisites for construction materials, design parameters, testing techniques, and construction practices. They serve as a reference to guarantee consistency, safety, and excellence in civil engineering projects throughout India. List of IS Codes for Civil Engineering IS Code for Cement and Concrete IS 269:1989: Ordinary Portland cement, OPC 33 IS 383:1970: Coarse and Fine aggregates from natural sources for concrete IS 455:1989: Portland slag cement IS 456:2000: Code of practice for plain concrete and reinforced concrete (PCC and RCC) IS  code >>> read more
Post a Comment
Next ⏭️