Vidaara.orgClass 8 · Mathematics
CodeVID-M8-WS
Heat and Temperature — Practice Worksheet
Name: ____________________
Roll No.: __________
Date: ____________
General Instructions
- All questions are compulsory.
- Choose the correct option (A, B, C or D) for each question.
- The answer key is at the end — try the paper first!
Section A — Multiple Choice (1 mark each)
25 × 1 = 25 marks
1.
Heat is best described as a:
- A.Measure of hotness
- B.Form of energy
- C.Type of force
- D.Type of light
2.
Temperature is a measure of:
- A.Total energy
- B.How hot or cold an object is
- C.Mass
- D.Volume
3.
Heat flows from an object at ______ temperature to one at ______ temperature.
- A.Lower; higher
- B.Higher; lower
- C.Equal; equal
- D.Zero; high
4.
The SI unit of heat is the:
- A.Kelvin
- B.Joule
- C.Newton
- D.Pascal
5.
A cup and a bucket of water are both at 100 °C. The bucket has:
- A.Lower temperature
- B.More heat energy
- C.Less heat energy
- D.No heat
6.
A common liquid thermometer works on the principle of:
- A.Reflection
- B.Expansion of a liquid with heat
- C.Magnetism
- D.Friction
7.
A clinical thermometer is used to measure the temperature of the:
- A.Air
- B.Human body
- C.Boiling water
- D.Ice
8.
On the Celsius scale, the boiling point of water is:
- A.0 °C
- B.100 °C
- C.212 °C
- D.273 °C
9.
On the Kelvin scale, water freezes at:
- A.0 K
- B.100 K
- C.273 K
- D.373 K
10.
The kink in a clinical thermometer is used to:
- A.Increase the range
- B.Hold the reading after removal
- C.Cool the liquid
- D.Measure pressure
11.
The Celsius and Kelvin scales are related by:
- A.K = C − 273
- B.K = C + 273
- C.K = C × 273
- D.K = 273 − C
12.
To convert Celsius to Fahrenheit, use:
- A.F = (9/5)C + 32
- B.F = (5/9)C − 32
- C.F = C + 273
- D.F = C − 32
13.
27 °C in Kelvin is:
- A.27 K
- B.300 K
- C.246 K
- D.273 K
14.
100 °C in Fahrenheit is:
- A.100 °F
- B.180 °F
- C.212 °F
- D.273 °F
15.
The combined relation between scales is:
- A.C/9 = (F−32)/5 = K
- B.C/5 = (F−32)/9 = (K−273)/5
- C.C = F = K
- D.C/5 = F/9 = K/273
16.
The transfer of heat through a solid without the solid moving is called:
- A.Convection
- B.Conduction
- C.Radiation
- D.Reflection
17.
Heat transfer in liquids and gases by the movement of the fluid is called:
- A.Conduction
- B.Convection
- C.Radiation
- D.Refraction
18.
Heat transfer that needs no medium and can occur through a vacuum is:
- A.Conduction
- B.Convection
- C.Radiation
- D.Insulation
19.
The Sun's heat reaches the Earth mainly by:
- A.Conduction
- B.Convection
- C.Radiation
- D.Friction
20.
Which of these is a good conductor of heat?
- A.Wood
- B.Plastic
- C.Metal
- D.Air
21.
Most substances, when heated, will:
- A.Contract
- B.Expand
- C.Stay exactly the same
- D.Disappear
22.
A bimetallic strip bends on heating because its two metals:
- A.Have the same expansion
- B.Expand by different amounts
- C.Do not expand
- D.Melt
23.
The heat needed to raise the temperature of a substance is given by:
- A.Q = mcΔT
- B.V = IR
- C.F = ma
- D.P = F/A
24.
The heat absorbed when a substance changes state without a temperature change is called:
- A.Specific heat
- B.Latent heat
- C.Thermal expansion
- D.Conduction
25.
Water is used as a coolant because it has a high:
- A.Density
- B.Specific heat capacity
- C.Colour
- D.Speed
Answer Key
Section A — Multiple Choice (1 mark each)
- (B) Form of energy
- (B) How hot or cold an object is
- (B) Higher; lower
- (B) Joule
- (B) More heat energy
- (B) Expansion of a liquid with heat
- (B) Human body
- (B) 100 °C
- (C) 273 K
- (B) Hold the reading after removal
- (B) K = C + 273
- (A) F = (9/5)C + 32
- (B) 300 K
- (C) 212 °F
- (B) C/5 = (F−32)/9 = (K−273)/5
- (B) Conduction
- (B) Convection
- (C) Radiation
- (C) Radiation
- (C) Metal
- (B) Expand
- (B) Expand by different amounts
- (A) Q = mcΔT
- (B) Latent heat
- (B) Specific heat capacity
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