Tag: clothes - our necessity

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Questions Related to clothes - our necessity

Multiple choice physics temperature and heat applications of heat conduction applications of insulation clothes - our necessity
Metal floors cool more than a wood floor in winters because:

  1. Metal conducts heat more readily than wood

  2. Wood conducts heat more readily than metal

  3. Metal has a higher specific heat than wood

  4. The temperature of the wood is higher than the temperature of the metal

  5. The temperature of the metal is higher than the temperature of the wood
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Metals are good conductor of heat whereas wood does not conduct heat at all.

Thus in winters, metal floors cool more than a wood floor.

Multiple choice physics transfer of heat applications of heat conduction applications of insulation clothes - our necessity

__and__are good conductors of heat

  1. Silver, Copper

  2. Wood,Plastic

  3. Glass,Paper

  4. Pure water,Iron
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation
Silver and copper are good conductors of heat.
$\because$ Silver and copper are only metals present there and as we know metals have conductivity of heat and electricity than non-metal and metalloids. So, silver and copper are god conductors of heat.
Multiple choice physics transfer of heat applications of heat conduction applications of insulation clothes - our necessity

State the correct statement

  1. When we heat an object, it becomes hot

  2. When we heat an object, it expands in size

  3. When we heat an object, it changes its such such as water boils to form water vapour

  4. All of them are true
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

When we heat an object, it changes its shape, nature and it becomes hot, the temperature increases due to movement of atoms.

Multiple choice physics transfer of heat applications of heat conduction applications of insulation clothes - our necessity

The ............ the conductor, the more rapidly does heat transfer takes place.

  1. better

  2. worse

  3. thinner

  4. thicker
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The better the conductor, the more rapidly does heat transfer takes place .


Better conductor means more thermal conductivity; more the thermal conductivity; more rapidly the heat transfer takes place.

Multiple choice physics transfer of heat applications of heat conduction applications of insulation clothes - our necessity

The reason for providing copper bottoms in steel pans is :

  1. aesthet, carly looks good

  2. that copper is better conductor than steel

  3. that copper is not a good conductor than steel

  4. None of the above

Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Copper bottoms are provided in steel pans because copper is better conductor of heat than steel.

Thermal conductivity of copper is highest ($38600w/mK$) while that of steel is lowest ($1245w/mK$).

Multiple choice physics transfer of heat applications of heat conduction applications of insulation clothes - our necessity

Four rods of same material but with different radii and lengths are used to connect two reservoirs of heat with the same temperature difference. Which one will conduct more heat

  1. r=1 cm, 1=1 cm

  2. r=1 cm, 1= 2 cm
  3. r= 1 cm, $1=\frac{1}{2}m$
  4. $r=\frac{1}{2}cm$, $1=\frac{1}{2}m$
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Heat conduction rate H = k*A*(delta T)/L. Since material and delta T are constant, H is proportional to A/L, or (r^2)/L. Calculating r^2/L for each: A) 1/1=1, B) 1/2=0.5, C) 1/0.5=2, D) 0.25/0.5=0.5. Option C gives the highest value.

Multiple choice physics transfer of heat applications of heat conduction applications of insulation clothes - our necessity

Which of the following arrangements is correct on the basis of conductivity of materials?

  1. Silver > copper > aluminium > tungsten

  2. Silver > aluminium > copper > tungsten

  3. Copper > silver >tungsten> aluminium

  4. Silver > tungsten > copper > aluminium
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Electrical conductivity is highest in silver, followed by copper, then aluminium, and then tungsten. Silver is the best electrical conductor among all metals.