This minimizes heat loss through radiation
johnmulu answered the question on February 6, 2017 at 13:02
-
An electric heater is placed at equal distances from two similar metal cans A and B filled with water at room temperature
(Solved)
An electric heater is placed at equal distances from two similar metal cans A and B filled with water at room temperature. The outer surface of can A is shiny while that of can B is dull black. State with reasons which can will be at higher temperature after the heater is switched on for some time.
Date posted:
February 6, 2017
.
Answers (1)
-
A wooden bench and a metal bench are both left in the sun for a long time. Explain why the metal bench feels hotter to touch
(Solved)
A wooden bench and a metal bench are both left in the sun for a long time. Explain why the metal bench feels hotter to touch.
Date posted:
February 6, 2017
.
Answers (1)
-
Give reason why heat transfer by radiation is faster than heat transfer by conduction
(Solved)
Give reason why heat transfer by radiation is faster than heat transfer by conduction.
Date posted:
February 6, 2017
.
Answers (1)
-
State two variables that must be controlled in an experiment for comparing the thermal conductivities of different metal rods of the same diameter
(Solved)
State two variables that must be controlled in an experiment for comparing the thermal conductivities of different metal rods of the same diameter.
Date posted:
February 6, 2017
.
Answers (1)
-
When a liquid is heated in a glass flask, its level at first falls then rises. Explain this observation
(Solved)
When a liquid is heated in a glass flask, its level at first falls then rises. Explain this observation.
Date posted:
February 6, 2017
.
Answers (1)
-
Clinical thermometer has a constriction in the bore just above the bulb. State the use of this constriction
(Solved)
Clinical thermometer has a constriction in the bore just above the bulb. State the use of this constriction.
Date posted:
February 6, 2017
.
Answers (1)
-
Why is water not a suitable liquid for use in a barometer?
(Solved)
Give reason why water is not a suitable liquid for use in a barometer.
Date posted:
February 6, 2017
.
Answers (1)
-
Explain why a glass container with thick walls is more likely to crack than one with a thin wall when a very hot liquid is poured into it.
(Solved)
Explain why a glass container with thick walls is more likely to crack than one with a thin wall when a very hot liquid is poured into it.
Date posted:
February 6, 2017
.
Answers (1)
-
Give a reason why a concrete beam reinforced with steel does not crack when subjected to changes in temperature
(Solved)
Give a reason why a concrete beam reinforced with steel does not crack when subjected to changes in temperature.
Date posted:
February 6, 2017
.
Answers (1)
-
One property of a liquid that is considered while constructing a liquid-in-glass thermometer is that the liquid expands more than the glass for the same temperature change
(Solved)
One property of a liquid that is considered while constructing a liquid-in-glass thermometer is that the liquid expands more than the glass for the same temperature change. State any other two properties of the liquids that are considered.
Date posted:
February 6, 2017
.
Answers (1)
-
State why it is easier to separate water into drops than to separate a solid into smaller pieces
(Solved)
State why it is easier to separate water into drops than to separate a solid into smaller pieces
Date posted:
February 6, 2017
.
Answers (1)
-
In a smoke cell experiment to demonstrate Brownian motion, smoke particles are seen moving randomly. State the cause of the randomness
(Solved)
In a smoke cell experiment to demonstrate Brownian motion, smoke particles are seen moving randomly. State the cause of the randomness
Date posted:
February 6, 2017
.
Answers (1)
-
A drop of blue ink is introduced at the bottom of a beaker containing water. It is observed that after sometime, all water in the beaker turns blue
(Solved)
A drop of blue ink is introduced at the bottom of a beaker containing water. It is observed that after sometime, all water in the beaker turns blue. Name the process that takes place.
Date posted:
February 6, 2017
.
Answers (1)
-
A bottle containing a smelling gas is opened at the front bench of a classroom. State the reason why the gas is detected throughout the room
(Solved)
A bottle containing a smelling gas is opened at the front bench of a classroom. State the reason why the gas is detected throughout the room.
Date posted:
February 6, 2017
.
Answers (1)
-
State the reason why it is easier to separate water into drops than to separate a solid into smaller pieces
(Solved)
State the reason why it is easier to separate water into drops than to separate a solid into smaller pieces
Date posted:
February 6, 2017
.
Answers (1)
-
Two identical beakers A and B containing equal volumes of water are placed on a bench. The water in A is cold while in B it is warm
(Solved)
Two identical beakers A and B containing equal volumes of water are placed on a bench. The water in A is cold while in B it is warm. Identical pieces of potassium permanganate are placed gently at the bottom of each beaker inside the water. It is observed that the spread of colour in B is faster than in A. Explain this observation
Date posted:
February 6, 2017
.
Answers (1)
-
Explain the difference between a liquid and a gas in terms of intermolecular distances and forces
(Solved)
Explain the difference between a liquid and a gas in terms of intermolecular distances and forces.
Date posted:
February 6, 2017
.
Answers (1)
-
Distinguish between solid and liquid states of matter in terms of intermolecular forces
(Solved)
Distinguish between solid and liquid states of matter in terms of intermolecular forces.
Date posted:
February 6, 2017
.
Answers (1)
-
Two identical tubes A and B held horizontally contain air and water respectively. A small quantity of coloured gas is introduced at one end of A
(Solved)
Two identical tubes A and B held horizontally contain air and water respectively. A small quantity of coloured gas is introduced at one end of A while a small quantity of coloured water is introduced at one end of B. State with reason the tube in which the colour will reach the other end faster.
Date posted:
February 6, 2017
.
Answers (1)
-
Explain the cause of random motion of smoke particles as observed in Brownian motion experiment using a smoke cell
(Solved)
Explain the cause of random motion of smoke particles as observed in Brownian motion experiment using a smoke cell.
Date posted:
February 6, 2017
.
Answers (1)