Numericals - Temperature

Temperature Scale Numericals

Learn Celsius, Fahrenheit and Kelvin conversions with animated formula cards, converter, thermometer, solved numericals and quiz.

Class 7 Physics

Heat Chapter

ICSE Practice

Interactive Numericals

Important Formulae

Celsius to Fahrenheit

F = 9C/5 + 32

Use this when Celsius value is given.

Fahrenheit to Celsius

C = 5(F − 32)/9

Use this when Fahrenheit value is given.

Celsius to Kelvin

K = C + 273

Kelvin reading is 273 more than Celsius.

Interactive Temperature Converter

Celsius to Fahrenheit Fahrenheit to Celsius Celsius to Kelvin Kelvin to Celsius

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The thermometer height will change with the value.

Step-by-Step Practice Tool

Choose a sample question:

1°C rise to Fahrenheit and Kelvin 18°F rise to Celsius Convert 5°F to Celsius Convert 40°C to Fahrenheit and Kelvin Convert −40°F to Celsius

Learning Progress

C. Numericals

Question 1

The temperature of a body rises by 1°C. What is the corresponding rise on the:
(a) Fahrenheit scale
(b) Kelvin scale?

100 divisions on Celsius scale = 180 divisions on Fahrenheit scale.

1°C rise = 180/100 = 1.8°F rise.

100 divisions on Celsius scale = 100 divisions on Kelvin scale.

1°C rise = 1 K rise.

Answer: (a) 1.8°F rise   (b) 1 K rise

Question 2

The temperature rises by 18°F. What is the rise on the Celsius scale?

180°F rise = 100°C rise.

18°F rise = 100/180 × 18

= 10°C

Answer: 10°C rise

Question 3

Convert 5°F to the Celsius scale.

Formula: C = 5/9 × (F − 32)

C = 5/9 × (5 − 32)

C = 5/9 × (−27)

C = −15°C

Answer: 5°F = −15°C

Question 4

Convert 40°C to:
(a) Fahrenheit scale
(b) Kelvin scale

For Fahrenheit: F = 9C/5 + 32

F = 9 × 40 / 5 + 32

F = 72 + 32 = 104°F

For Kelvin: K = C + 273

K = 40 + 273 = 313 K

Answer: (a) 104°F   (b) 313 K

Question 5

Convert −40°F to the Celsius scale.

Formula: C = 5/9 × (F − 32)

C = 5/9 × (−40 − 32)

C = 5/9 × (−72)

C = 5 × (−8)

C = −40°C

Answer: −40°F = −40°C

Remember: A rise of 1°C is equal to a rise of 1 K. But the actual readings on Celsius and Kelvin scales are different because Kelvin starts from absolute zero.

Quick Quiz

Match the Formula

Click one card below and learn where it is used:

F = 9C/5 + 32

C = 5(F − 32)/9

K = C + 273

FAQs

What is the formula to convert Celsius to Fahrenheit?

The formula is F = 9C/5 + 32.

What is the formula to convert Fahrenheit to Celsius?

The formula is C = 5(F − 32)/9.

What is the formula to convert Celsius to Kelvin?

The formula is K = C + 273.

Why is −40°F equal to −40°C?

When −40 is placed in the formula C = 5(F − 32)/9, the answer becomes −40°C.

Is a rise of 1°C equal to a rise of 1 K?

Yes. A rise of 1°C is equal to a rise of 1 K.