CBSE Class 12 Physics Thermal Expansion Solved Examples

Scroll down for PDF

 

CBSE Class 12 Physics Thermal Expansion Solved Examples. Please refer to the examination notes which you can use for preparing and revising for exams. These notes will help you to revise the concepts quickly and get good marks.

Ex.1 A clock which keeps correct time at 25ºC has a pendulum made of brass whose coefficient of linear expansion is 0.000019. How many seconds a day will it gain if the temperature fall to 0ºC.
Sol. Let L0 and L25 be the length of pendulum at 0ºC and 25ºC respectively.

class_12_physics_useful_0522

Ex. 2 A steel tape gives correct reading at 20°C. A piece of wood is being measured with the steel tape at 0°C. The reading is 25 cm on the tape.State whether the real length of the wood is more than or less than or equal to 25 cm.

class_12_physics_useful_0523

Sol. The steel expands on heating and contracts on cooling. Given that tape gives correct reading at 20°C. At 0°C. the tape contracts. The situations at 0°C and 20°C are shown in figure. Obviously real length of the wood is less than 25 cm.

Ex.3 A metal disc has a hole in it. What happens to size of hole when disc is heated?
Sol. On heating the size of hole increases.

Ex.4 A circular hole in an aluminium plate is 2.54 cm in diameter at 0°C. What is the diameter when the temperature of the plate is raised to 100°C ? 

Given

class_12_physics_useful_0524

Ex.5 A pendulum clock keeps correct time at 0°C. Mean coefficient of linear expansion is a per °C. If the temperature of the room increases by t°C, then show that the clock loses per day by

class_12_physics_useful_0525

[For section pendulum time period is 2 sec i.e. T0/2 = 1 sec.]
If n0 and nt are number of seconds in one day, then

class_12_physics_useful_0526

Ex.6 If the volume of a block of a metal changes by 0.12% when it is heated through 20°C, what is the coefficient of linear expansion of metal?
Sol. Coefficient of cubical expansion of metal is given by
 

class_12_physics_useful_0527

 

Click on the text For more study material for Physics please click here - Physics

Latest NCERT & CBSE News

Read the latest news and announcements from NCERT and CBSE below. Important updates relating to your studies which will help you to keep yourself updated with latest happenings in school level education. Keep yourself updated with all latest news and also read articles from teachers which will help you to improve your studies, increase motivation level and promote faster learning

CBSE will have more practicals

CBSE board has made a bigger announcement regarding 2020 board examinations for class 12. Board has decided that subjects like humanities, History, English and Hindi will also have practical exams like Chemistry, Biology, and Physics. As per, CBSE official's statement...

CBSE schools to have sports period daily for classes 1 to 12

CBSE schools to have sports period daily for classes 1 to 12, new curriculum introduced All work and no play makes a child dull. Nowadays students have a very hectic schedule so that they cannot take out time to play games and gently start ignoring sports. Therefore,...

UP government schools will follow NCERT

UP government schools will follow NCERT pattern from April 2020Are you appearing for the UP exams 2020? If yes, then you have to see what major changes UP government schools have brought for 2020.The UP government is fully prepared to implement NCERT pattern for...

IBM to Set AI Curriculum for CBSE Class IX to XII

The Central Board of Secondary Education has tied up with IBM to develop a course of Artificial Intelligence in the CBSE curriculum. Now CBSE is going to introduce Artificial Intelligence as an elective subject for class 9 to 12th. The CBSE has taken this decision to...

Top Classroom Challenges According to the Teachers

Teacher plays a major role in our lives in the classrooms. Not only is studying, but the teacher also serves many other roles in the classrooms. A teacher is always a role model for a student who can inspire him to live a better future life. Besides this, life of a...

Sample Papers for Class 10 Boards 2020

CBSE has recently released the Class 10 Sample Papers for Board exams which are to be held in March 2020. The sample papers have been for class 10 for all subjects along with the suggested marking scheme. CBSE releases these suggested papers every year so that the...

×
Studies Today