Tag: lightning safety

Questions Related to lightning safety

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

Show answer
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

Show answer
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.

Assertion : An earthquake will not cause uniform damage to all building in an affected area, even if they are built with the same strength and materials.
Reason : The one with its natural frequency close to the frequency of seismic wave is likely to be damaged less.

physics structure of earth seismic waves and tsunami causes of earthquakes origin of earth and its internal energy transfer of charge lightning safety

  1. If both assertion and reason are true and reason is the correct explanation of assertion.

  2. If both assertion and reason are true and reason is not the correct explanation of assertion.

  3. If assertion is true but reason is false.

  4. If both assertion and reason are false.

Show answer
Correct Option: C
Explanation:

An earth quake will not cause uniform damage to all building in an affected area because the natural frequencies of a building depend on its height and other size parameters and the nature of building materials.
The one with its natural frequency close to the frequency of seismic wave is likely to be damaged more.

An earthquake generates both transverse $(S)$ and longitudinal $(P)$ sound waves in the earth. The speed of $S$ waves is about $4 \,\,km \,\,s^{-1}$ and that of $P$ waves is about $8 \,\,km \,\,s^{-1}$. A seismograph records $P$ and $S$ waves from an earthquake.The first $P$ wave arrives $4$ min before the first $S$ wave. The epicentre of the earthquake is located at a distance of about

physics structure of earth seismic waves and tsunami causes of earthquakes origin of earth and its internal energy transfer of charge lightning safety

  1. $192 km$

  2. $384 km$

  3. $1920 km$

  4. $3840 km$

Show answer
Correct Option: C
Explanation:
Let $\nu _1, \nu _2$ be speed $S$ of $S$ and $P$ waves and $t _1,t _2$ be the time taken by these waves to travel to reach the seismograph. Let the epicenter of the earthquake is located at a distance $d$ from the seismograph. Then,
$d = V _1 t _1 = V _2 t _2$          ................ .....(i)
Here, $V _1 = 4 km \,\,s^{-1}$ and $V _2 = 8 km \,\,s^{-1}$
$\therefore 4t _1 = 8t _2 \Longrightarrow t _1 = 2t _2$           ....(ii)
and  $t _1 - t _2 = 4 min = 240 s$
$\therefore 2t _2 - t _2 = 240$      ....................  [using (ii)]
or $t _2 = 240 s$
put in Eq. (ii), we get,
$t _1 = 2 \times 240 s = 480 s$
From Eq. (i), we get, $d = (4 km \,\,s^{-1}) (480 s) = 1920 km$

The weak zone around the boundaries of plates underneath the Earth, which is prone to slide and cause an earthquake is commonly known as :

physics structure of earth seismic waves and tsunami causes of earthquakes origin of earth and its internal energy transfer of charge lightning safety

  1. Fault zone

  2. Eruption zone

  3. Explosive zone

  4. Sliding zone

Show answer
Correct Option: A
Explanation:

The weak zone around the boundaries of plates underneath the Earth, which  is prone to slide and cause an earthquake is known as Seismic or Fault Zones.

The correct option is A.

Seismic waves is recorded by an instrument called seismograph.

physics structure of earth seismic waves and tsunami causes of earthquakes origin of earth and its internal energy transfer of charge lightning safety

  1. True

  2. False

Show answer
Correct Option: A

The natural calamity that cannot be predicted accurately in advance:

physics structure of earth seismic waves and tsunami causes of earthquakes origin of earth and its internal energy transfer of charge lightning safety

  1. Flood

  2. Cyclone

  3. Earthquake

  4. Famine

Show answer
Correct Option: C

Which of the following country in the world is most prone to earthquake?

physics structure of earth seismic waves and tsunami causes of earthquakes origin of earth and its internal energy transfer of charge lightning safety

  1. India

  2. America

  3. China

  4. Japan

Show answer
Correct Option: D
Explanation:

Japan is the country in the world is most prone to earthquake.