All Exams Test series for 1 year @ ₹349 only
Question

The temperature T in a room varies as a function of the outside temperature T0 and the number of persons in the room p, according to the relation T = K (θp + T0), where θ and K are constants. What would be the value of θ, which gives the following data?

T0

p

T

25

2

32.4

30

5

42.0

The correct answer is

1.0

Temperature Relation Analysis

The problem presents a relation describing the temperature T in a room. This room temperature T depends on the outside temperature T0 and the number of persons in the room p. The given mathematical relation is \( \text{T} = \text{K} (\theta\text{p} + \text{T}_0) \), where \( \theta \) and \( \text{K} \) are constants. Our goal is to determine the value of \( \theta \) using the provided experimental data.

Data Interpretation for Temperature Calculation

We are given two sets of data points, each showing a specific room temperature T corresponding to a particular outside temperature T0 and number of persons p. This data is crucial for forming equations to solve for the unknown constants.

\( \text{T}_0 \) \( \text{p} \) \( \text{T} \)
25 2 32.4
30 5 42.0

Setting Up the Temperature Equations

We can substitute each set of data into the given temperature relation \( \text{T} = \text{K} (\theta\text{p} + \text{T}_0) \) to form two linear equations. These equations will involve the two unknown constants, \( \text{K} \) and \( \theta \).

  • Equation 1 (Using Data Set 1: \( \text{T}_0 = 25, \text{p} = 2, \text{T} = 32.4 \)): \[ 32.4 = \text{K} (\theta(2) + 25) \] \[ 32.4 = \text{K} (2\theta + 25) \quad \ldots(1) \]
  • Equation 2 (Using Data Set 2: \( \text{T}_0 = 30, \text{p} = 5, \text{T} = 42.0 \)): \[ 42.0 = \text{K} (\theta(5) + 30) \] \[ 42.0 = \text{K} (5\theta + 30) \quad \ldots(2) \]

Solving for Theta ($\theta$) in the Temperature Equation

Now we have a system of two equations with two unknowns, \( \text{K} \) and \( \theta \). We can solve for \( \theta \) by first expressing \( \text{K} \) in terms of \( \theta \) from one equation and then substituting it into the other.

  • From Equation (1), we can express \( \text{K} \): \[ \text{K} = \frac{32.4}{2\theta + 25} \]
  • Substitute this expression for \( \text{K} \) into Equation (2): \[ 42.0 = \left(\frac{32.4}{2\theta + 25}\right) (5\theta + 30) \]
  • Multiply both sides by \( (2\theta + 25) \) to eliminate the denominator: \[ 42.0 (2\theta + 25) = 32.4 (5\theta + 30) \]
  • Distribute the constants on both sides: \[ 84\theta + 1050 = 162\theta + 972 \]
  • Gather the \( \theta \) terms on one side and the constant terms on the other: \[ 1050 - 972 = 162\theta - 84\theta \] \[ 78 = 78\theta \]
  • Finally, solve for \( \theta \): \[ \theta = \frac{78}{78} \] \[ \theta = 1.0 \]

Calculating the Constant K (Optional Verification)

Although the question only asks for \( \theta \), we can find the value of \( \text{K} \) to ensure consistency and for a complete understanding of the relationship. Substitute the calculated value of \( \theta = 1.0 \) back into the expression for \( \text{K} \):

\[ \text{K} = \frac{32.4}{2\theta + 25} = \frac{32.4}{2(1.0) + 25} = \frac{32.4}{2 + 25} = \frac{32.4}{27} \] \[ \text{K} = 1.2 \]

Final Temperature Verification

To confirm our values, we can plug \( \theta = 1.0 \) and \( \text{K} = 1.2 \) back into the original relation for both data sets.

  • For Data Set 1: \( \text{T}_0 = 25, \text{p} = 2 \) \[ \text{T} = 1.2 (1.0(2) + 25) = 1.2 (2 + 25) = 1.2 (27) = 32.4 \] This matches the given temperature.
  • For Data Set 2: \( \text{T}_0 = 30, \text{p} = 5 \) \[ \text{T} = 1.2 (1.0(5) + 30) = 1.2 (5 + 30) = 1.2 (35) = 42.0 \] This also matches the given temperature.

Both verifications confirm that the calculated value of \( \theta = 1.0 \) is correct.

Was this answer helpful?

Important Questions from Data Interpretation

  1. The table shows the monthly expenditure of Saumya. What percent of her monthly salary is she able to save?

    ExpenseAmount
    Food5,000
    Rent20,000
    Travel10,000
    Clothing3,000
    Miscellaneous15,000
    Savings7,500

  2. What does the height of the rectangle in a histogram show?

  3. Following table provides figures (in rupees) on annual expenditure of a firm for two years – 2010 and 2011.

    Category

    2010

    2011

    Raw material

    5200

    6240

    Power & fuel

    7000

    9450

    Salary & wages

    9000

    12600

    Plant & machinery

    20000

    25000

    Advertising

    15000

    19500

    Research & Development

    22000

    26400

    In 2011, which of the following two categories have registered increase by same percentage?

  4. Read the following table giving sales data of five types of batteries for years 2006 to 2012

    Year

    Type I

    Type II

    Type III

    Type IV

    Type V

    2006

    75

    144

    114

    102

    108

    2007

    90

    126

    102

    84

    126

    2008

    96

    114

    75

    105

    135

    2009

    105

    90

    150

    90

    75

    2010

    90

    75

    135

    75

    90

    2011

    105

    60

    165

    45

    120

    2012

    115

    85

    160

    100

    145


    Out of the following which type of battery achieved highest growth between the years 2006 and 2012?
  5. Each of the letters arranged as below represents a unique integer from 1 to 9. The letters are positioned in the figure such that (A × B × C), (B × G × E) and (D × E × F) are equal. Which integer among the following choices cannot be represented by the letters A, B, C, D, E, F and G?

    A

    D

    B

    G

    E

    C

    F

Need Expert Advice?

Start Your Preparation with Prepp Mobile App

Download the app from Google Play & App Store
Download the app from Google Play & App Store
Prepp Mobile App