Heat Test

Result

Heat Test - 35

Score
-
out of -
Rank
-
out of -

TIME Taken - -

SHARING IS CARING

If our Website helped you a little, then kindly spread our voice using Social Networks. Spread our word to your readers, friends, teachers, students & all those close ones who deserve to know what you know now.

Weekly Quiz Competition

Question 1
1 / -0

If the temperature of a hot body is increased by 50% then the increase in the quantity of emitted heat radiation will be

A
125%

B
200%

C
300%

D
400%

Solution

let us assume initial Temperature $$T_1=T$$ then final will be

$$T_2=\dfrac{50}{100}T+T=\dfrac{150}{100}T=\dfrac{15}{10}T$$

energy radiated

$$e_1=\sigma A T_1^4\quad \left(1\right)$$

$$e_2=\sigma A T_2^4\quad \left(2\right)$$

$$\%$$ increase in radiation

$$=\dfrac{e_2-e_1}{e_1}\times 100$$

$$=\dfrac{\sigma A T_2^4-\sigma A T_1^4}{\sigma A T_1^4}\times 100$$

$$\dfrac{\left(\dfrac{15}{10}T\right)^4-T^4}{T^4}\times 100$$

$$\dfrac{15^4-10^4}{10^4}\times 10^2$$

$$\dfrac{50625-10000}{10^2}$$

$$=406.25$$

$$\approx 400\%$$
Hence $$(d)$$ option is correct.
Question 2
1 / -0

Two thermometers are used to record the temperature of a room and the bulb of one is wrapped in a wet hanky.

A
The temperature recorded by both will be same

B
The temperature recorded by the wet-bulb thermometer will be greater than that recorded by the other

C
The temperature recorded by dry-bulb thermometer will be greater than that recorded by the other

D
None of the above

Solution

The temperature recorded by the dry bulb thermometer will be greater. Due to evaporation cooling is caused which lowers the temperature of the bulb wrapped in a wet hanky.
Question 3
1 / -0

Boojho has three thermometers as shown in above Figure. He wants to measure the temperature of his body and that of boiling water. Which thermometer (s) should he choose?

A
Thermometer (i) or (iii) for measuring body temperature and (ii) for measuring the temperature of boiling water.

B
Thermometer (i) for measuring temperature of both.

C
Thermometer (ii) for measuring temperature of both.

D
Thermometer (iii) for measuring temperature of both.

Solution

The image (I) and (III) are the clinical thermometers that are used to measure the body temperature only.
The correct answer is option (a). Thermometer (i) or (iii) for measuring body temperature and (ii) for measuring the temperature of boiling water.
Question 4
1 / -0

Mercury is often used in clinical thermometers. Which one of the following properties of mercury is not a reason for this ?

A
The coefficient of the thermal expansion is large

B
It is shiny

C
It is a liquid at room temperature

D
It has high density.

Solution

Mercury is used in thermometer as it has a high coefficient of expansion so even the smallest change in temperature can be observed, it is shiny so that we can see the level of mercury clearly and it is liquid for a wide range of temperature. But, high density of mercury is not the reason for its use in clinical thermometers.
Hence, OPTION : D.
Question 5
1 / -0

Two thermometers are constructed in such a way that one has a spherical bulb and the other has elongated cylindrical bulb. The bulbs are made of same material and thickness. Then :

A
spherical bulb will respond more quickly to temperature changes

B
cylindrical bulb will respond more quickly to temperature changes.

C
both bulbs will respond same to temperature changes

D
none of both bulbs respond to temperature changes

Solution
Question 6
1 / -0

A metal spoon is placed in one of two identical cups of hot coffee. Why does the cup with the spoon have a lower temperature after a few minutes ?

A
Energy is removed from the coffee mostly by conduction through the spoon.

B
Energy is removed from the coffee mostly' by convection through the spoon.

C
Energy is removed from the coffee mostly by radiation through the spoon.

D
None of these

Solution
Question 7
1 / -0

A student took an iron rod and a wooden rod and wrapped each of them in a piece of paper. These were then heated as shown. It was found that the paper around the iron rod does not burn whereas the one around the wooden rod catches fire.It is because

A
Candle, in case of iron rod, is nearer to the paper

B
Wood being a bad conductor of heat, takes away all the heat

C
Iron being a good conductor of heat, conducts away the heat give to the paper

D
Paper, in first case, is thicker

Solution
Question 8
1 / -0

___________ is a measure of the degree of hotness of an object.

A
Thermometer

B
Temperature

C
Radiation

D
None of these

Solution

Temperature is a measure of the degree of hotness of an object.
A thermometer is a device used for measuring temperature.
The transfer of heat in which no medium is required is known as radiation
Question 9
1 / -0

Why is sense of touch not reliable?

A
It doesn't tell us what is hot or cold

B
It doesn't work for all of us

C
It might misguide us

D
None of these

Solution

Sense of touch might misguide us and lead us to make wrong observations regarding the hotness or coldness of any object, thus option $$C$$ is correct.
Question 10
1 / -0

Weather reports are made using __________ thermometer

A
Clinical

B
Laboratary

C
Maximum-minimum

D
None of these

Solution

The maximum and minimum temperatures of the previous day, reported in weather reports, are measured by a thermometer called the maximum-minimum thermometer, thus option $$C$$ is correct.