A heater is used to boil water in a container. The heater supplies heat at a constant rate R. Water boils at 100°C. Assume that the water in the container loses heat to the atmosphere at a rate that is proportional to both, the temperature of the water as well as to the volume of water in the container. If this proportionality constant is K then the maximum volume of water that can be boiled by the heater is
The question asks for the maximum volume of water that can be boiled by a heater supplying heat at a constant rate \(R\).
Water boils at \(100^{\circ}C\). For water to continuously boil (or be maintained at \(100^{\circ}C\) while still receiving heat), the rate at which heat is supplied by the heater must be equal to the rate at which heat is lost to the surroundings at the boiling temperature.
We are given:
Let \(V\) be the volume of water in the container and \(T\) be the temperature of the water.
The heat loss rate can be expressed as:
\(\text{Heat loss rate} = K \times T \times V\)
When the water is boiling, its temperature is \(T = 100^{\circ}C\). So, the heat loss rate at the boiling point for a volume \(V\) is:
\(\text{Heat loss rate at } 100^{\circ}C = K \times 100^{\circ}C \times V\)
The maximum volume of water that can be boiled by the heater is limited by the heat supply rate \(R\). At the maximum volume, the entire heat supplied by the heater is used to compensate for the heat lost to the atmosphere at the boiling temperature (\(100^{\circ}C\)). If the volume were larger, the heat loss at \(100^{\circ}C\) would exceed \(R\), and the heater wouldn't be able to maintain the water at \(100^{\circ}C\).
So, at the maximum volume \(\left(V_{\text{max}}\right)\), the heat supplied rate equals the heat loss rate at \(100^{\circ}C\):
\(R = K \times 100 \times V_{\text{max}}\)
Now, we need to solve for \(V_{\text{max}}\):
\(V_{\text{max}} = \frac{R}{K \times 100}\)
\(V_{\text{max}} = \frac{R}{100K}\)
Comparing this result with the given options:
The calculated maximum volume matches Option 3.
For sustained boiling at \(100^{\circ}C\), the energy supplied by the heater must equal the energy lost to the surroundings. The heater supplies energy at rate \(R\). The energy loss rate is given by \(K \times \text{Temperature} \times \text{Volume}\). At \(100^{\circ}C\), this loss is \(K \times 100 \times V\). Setting the supply equal to the loss gives \(R = 100KV\).
Here are the steps to determine the maximum volume:
This formula gives the maximum volume of water that the heater can maintain at \(100^{\circ}C\) given the heat loss characteristics.
In an examination 10,000 students appeared. The result revealed the number of students who have:
passed in all five subjects = 5583
passed in three subjects only = 1400
passed in two subjects only = 1200
passed in one subject only = 735
failed in English only = 75
failed in Physics only = 145
failed in Chemistry only = 140
failed in Mathematics only = 200
failed in Bio-science only = 157
The number of students passed in at least four subjects is:
How many hollow spheres having inner radius of 1 cm can be completely filled by transferring water from a completely filled hollow sphere having inner diameter of 20 cm ?
The period of a pendulum is given as T = 2 π (l/g)1/2 where g = 9.81 m/s2 and π = 3.1416. The period of a pendulum of length 1 m correct to the first place of decimal in seconds is