Tag: introduction to electrostatics

Questions Related to introduction to electrostatics

Earthing is provided in buildings to protect it form

physics electric charges and fields conductors and insulators introduction to electrostatics electricity

  1. lightning

  2. leakage of electric current

  3. cyclone

  4. thunderstorm

Show answer
Correct Option: B
Explanation:

Earthing means to connect electrical system to earth or soil in such a manner as it ensures an immediate discharge of electrical energy night out any danger. it is essentially done to product the building from any miss happening.

Ordinary rubber is an insulator. But the special rubber tyres of aircrafts are made slightly conducting. Why is this necessary?

physics electric charges and fields conductors and insulators introduction to electrostatics electricity

  1. The charged developed due to atmospheric electricity finds its way to the earth

  2. The charged developed due to friction finds its way to the earth

  3. The charged developed due to induction finds its way to the earth

  4. The charged developed due to the aircraft engine finds its way to the earth

Show answer
Correct Option: B
Explanation:

Ordinary rubber is an insulator. But the special rubber tyres of aircrafts are made slightly conducting. This is because during landing or takeoff, the tyres of aircrafts get charged due to friction between tyres and the ground. In such case, the tyres are slightly conducting, the charges developed on the tyres will not stay on them and find its way to earth.

__________ is a good conductor of electricity.

physics electric charges and fields conductors and insulators introduction to electrostatics electricity

  1. Iodine

  2. Graphite

  3. Sulphur

  4. Bromine

Show answer
Correct Option: B
Explanation:

Non-metals are the bad conductor of electricity except one i.e Graphite(made of carbon).Hence iodine,sulphur and bromine do not conduct electricity.

State whether true or false:
Alcohol and ether are conducting liquids of electricity. 

physics electric charges and fields conductors and insulators introduction to electrostatics electricity

  1. True

  2. False

Show answer
Correct Option: A
Explanation:


Ionic Liquids like alcohol and ether frequently share a number of attractive properties that distinguish them from conventional organic solvents, such as low (and even effectively-null) vapor pressure, a wide liquid range, low flammability, high conductivity (e.g., ionic, thermal), excellent stability (e.g., thermal, chemical, redox, radiochemical), a wide electrochemical potential window, and the ability to act as surprisingly good solvents towards many substances.
Ionic Liquids are a new class of purely ionic, salt-like materials that are liquid at unusually low temperatures.
Hence, the statement is true.

State whether true or false :

A piece of fresh potato does not conduct electricity at all.

physics electric charges and fields conductors and insulators introduction to electrostatics electricity

  1. True

  2. False

Show answer
Correct Option: B
Explanation:

False.

A potato has the potential to conduct electricity because it is a source filled with electrolytes. These electrolytes act as an electrical conductor which means they allow the flow of electric charges.thus it will conduct electricity.

State whether true or false :

Rain water is a non-conductor of electricity.

physics electric charges and fields conductors and insulators introduction to electrostatics electricity

  1. True

  2. False

Show answer
Correct Option: B
Explanation:

False.

Rain water is a conductor of electricity due to The most common one is carbon dioxide. Carbon dioxide itself in not an electrolyte, but it reacts with water to make what is often called "carbonic acid". Carbonic acid is actually a fictitious acid, since there are no molecules of ${H} _{2}{CO} _{3}$ in aqueous solution. But what is present that makes rain water a conductor are $H^+$ and $HCO^{3-}$ ions. 

$CO _2$(aq) $+$ $H _2O$(l) <==> $H^+$ $+$ $HCO^{3-}$ 

$1000$ years ago, that would have pretty much been it. But today we have lots more pollutants in the air that contribute to acid rain and to the conductivity of rainwater. $SO _3$ dissolves in water to make $H _2SO _4$, which exists as $H^+$ and $HSO^{4-}$ ions. $N _2O _5$ dissolves in water to make $HNO _3$, which exists in water as $H^+$ and $NO^{3-}$. These are but a few of the substances that can produce the ions in solution that will make rainwater a conductor.

Which of the following is best insulator?

physics electric charges and fields conductors and insulators introduction to electrostatics electricity

  1. carbon

  2. paper

  3. ebonite

  4. graphite

Show answer
Correct Option: C
Explanation:

Out of the given options, ebonite is best insulator. Whereas, carbon and graphite are fair conductors and ebonite is a better insulator than paper.

State whether true or false.
Ebonite is a good conductor of electricity.

physics electric charges and fields conductors and insulators introduction to electrostatics electricity

  1. True

  2. False

Show answer
Correct Option: B
Explanation:

Given statement is that "ebonite is a good conductor of electricity". This statement is false. This is because ebonite is a poor conductor of electricity, it is an insulator. Electrons cannot move easily within it, and also it has no free electrons present for conductivity.

Ordinary tap water conducts electric current due to :

physics electric charges and fields conductors and insulators introduction to electrostatics electricity

  1. the dissolved salts in it

  2. higher purity of the water

  3. the bacteria present in it

  4. none of these

Show answer
Correct Option: A
Explanation:

Tap water conducts electricity since there are small amounts of calcium and magnesium salts dissolve in it, pure water (distilled or de-ionised) has nothing at all in it that can conduct electricity. This is because water itself isn't a conductor. However, when one dissolves ionic compound such as salts, the ions becomes loosely bound to each other which makes tap water a good conductor of electricity. 

An example in which light emitting diodes are used is :

physics electric charges and fields conductors and insulators introduction to electrostatics electricity

  1. calculator

  2. hard drive

  3. optical drive

  4. analog watch

Show answer
Correct Option: A
Explanation:

Light emitting diodes are used in calculators.


Option A is  correct.