Question

QII. Multiple Choice Questions:

1. Which of these is/are the unit(s) of heat energy?
Joule / Calorie / both (a) & (b) /none

2. Heat causes
Change in state / expansion / change in temperature / all of these

3. Ventilation in rooms occurs due to:
Conduction /convection /radiation /all of these

4.Heat from the sun reaches us due to:
Conduction / convection / radiation /all of these

5. Which of the following expands most on heating?
Sand /solids / water / gases​

Answer 1

Hello

1 calorie = 4.2 j

1J = 1 kg m2s–2

put the value we get =>

1 calorie =4.2 kg m2s–2 = 4.2 × (1 kg) × (1 m2) × (1 s–2) …(1)

Given that

Unit of mass equals α kg => 1 kg mass = 1/α mass

Unit of length equals β m => 1 m length = 1/ β length

Unit of time is γs => 1 s time = 1/ γ time

Put the values in equation (1), we get

New unit of mass = α kg

=4.2 × (1 kg) × (1 m2) × (1 s–2)

= 4.2 × (1/ α ) × (1/ β ) 2 × (1/ γ) –2

= 4.2 × ( α–1 ) × (β–1 ) 2 × ( γ–1) –2

=4.2 α–1 β–2 γ2