Tag: some natural phenomena

Questions Related to some natural phenomena

State whether true or false:
Lightning conductors are used to save the building from earthquakes.

physics some natural phenomena lightning conductors lightning safety advanced of lightning

  1. True

  2. False

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Correct Option: B
Explanation:

The given statement is false. This is because a lightening conductor is a metal rod mounted on buildings intended to protect the structure from the 'Lightening strike' and not from 'earthquakes'.

Which one of the following statements is CORRECT?

    physics some natural phenomena lightning conductors lightning safety advanced of lightning

    1. Lightning rods are made of insulators

    2. A conductor holds charge

    3. The earth is an insulator

    4. An insulator prevents charge from flowing

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    Correct Option: D
    Explanation:

    An insulator does not allow the electric current to flow through it. Insulator offers very high resistance to the flow of electric current (charge).

    The lightening conductor is connected to interface with ground or "earth" through

    physics some natural phenomena lightning conductors lightning safety advanced of lightning

    1. a cathode

    2. an anode

    3. an electrode

    4. a semiconductor

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    Correct Option: C
    Explanation:

    Conductor cables carry lightening current from lightening rod to the ground. Since electrode is an electrical conductor. So, the answer is "an electrode".

                          is engineered to protect an elevated structure in the event of lightning strike.

    physics some natural phenomena lightning conductors lightning safety advanced of lightning

    1. A lightning conductor

    2. Copper wire

    3. A lightening shield

    4. All of the above

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    Correct Option: A
    Explanation:

    A lightening conductor is a metal rod mounted on a structure and designed to protect the structure from lightening strike. 

    If the instantaneous current in a metallic wire is $i = \left( {5 + 10t} \right)A$ then find amount of charge flown through it from $t = 2s$ to $t = 3s$ is

    physics some natural phenomena lightning conductors lightning safety advanced of lightning

    1. 10 C

    2. 20 C

    3. 30 C

    4. 40 C

    Show answer
    Correct Option: C
    Explanation:

    Given instantaneous current,

    $i=(5+10t)A$
    and from the definition of instantaneous current,  $i=\dfrac { dq }{ dt } $
    $\Rightarrow \quad \left( 5+10t \right) =\dfrac { dq }{ dt } $
    $dq=\left( 5+10t \right) dt$
    Integrating implies,
    $Q=5t+{ 5t }^{ 2 }$
    At $t=2$,
                    ${ Q } _{ 1 }=30C$
    At $t=3$,
                    ${ Q } _{ 2 }=60C$

    $\therefore $  Option (C) is the correct option.

    Where is the lower end of a lightning conductor fixed in the building?

    physics some natural phenomena lightning conductors lightning safety advanced of lightning

    1. at the top

    2. at a window

    3. at the base

    4. in the ground

    Show answer
    Correct Option: A
    Explanation:

    a) It made from metal like Iron.
    b) Its top end is pointed.
    c) Obviously on the top of building far from any other metal.
    d) It is placed below the ground with a copper plate.

    The nature of charge on the object can be detected by:

    physics some natural phenomena transfer of charge types of charges and their interaction transfer of charges

    1. microscope

    2. electroscope

    3. electrometer

    4. telescope

    Show answer
    Correct Option: B
    Explanation:

    A pre-charged electroscope detects the nature of charge on a charged body.

    When a charge passes from a charged object to an uncharged one, the process is called:

    physics some natural phenomena transfer of charge types of charges and their interaction transfer of charges

    1. conduction

    2. induction

    3. discharging

    4. none of the above

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    Correct Option: A
    Explanation:

    Conduction is the process in which uncharged object acquires charge when it it brought in contact with the charged object.

    What happens when the end of the paper clip of electroscope is touched by hands?

    physics some natural phenomena transfer of charge types of charges and their interaction transfer of charges

    1. Electric current is produced 

    2. Foil strips remain as it is

    3. Foil strips collapse

    4. None of the above

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    Correct Option: C
    Explanation:

    Because the charges on foil strips gets discharge through air body as soon as paper clip of electroscope is touched by hand, the foil strips collapse.

    Opening up of strips of an electroscope is an indication of:

    physics some natural phenomena transfer of charge types of charges and their interaction transfer of charges

    1. proximity of a conductor.

    2. proximity of a charged body.

    3. proximity of an uncharged body.

    4. earth connection.

    Show answer
    Correct Option: B
    Explanation:

    When a charged body comes close to an electroscope, charges are induced to the electroscope. These charges flow down to the metal strips which open up due to repulsion for having similar charges.