8th Standard Syllabus & Materials
8th Standard
Tamilnadu 8th Standard கணிதம் இயற்கணிதம் Important Questions And Answers Study Material - QB365
NEW8th Standard
Tamilnadu 8th Standard கணிதம் எண்கள் Important Questions And Answers Study Material - QB365 Set B
NEW8th Standard
Tamilnadu 8th Standard கணிதம் எண்கள் Important Questions And Answers Study Material - QB365 Set A
NEW8th Standard
Tamilnadu 8th Standard Social Science பொருளியல் - பொது மற்றும் தனியார் துறைகள் Important Questions And Answers Study Material - QB365
NEW8th Standard
Tamilnadu 8th Standard Social Science குடிமையியல் - நீதித்துறை Important Questions And Answers Study Material - QB365
NEW8th Standard
Tamilnadu 8th Standard Social Science குடிமையியல் - பாதுகாப்பு மற்றும் வெளியுறவுக் கொள்கை Important Questions And Answers Study Material - QB365
Published on: 13/05/2022
QB365 provides detailed and simple solution for every Book back Questions in class 8 Science Subject. It will helps to get more idea about question pattern in every book back questions with solution.
latest Book back QuestionsDownload Tamil Nadu 8th Standard Science question papers, model tests, one-mark questions, important questions, and public exam papers in PDF format. Free study materials and answer keys for TN State Board students.
Questions + Answers key
Take MCQ Science Test1.
What is vibration?
2.
To increase the loudness of sound by four times, how much should the amplitude of vibration be changed?
3.
Give two differences between music and noise.
4.
A sound wave travels 2000 m in 8 s. What is the velocity of the sound?
5.
A wave with a frequency of 500 Hz is traveling at a speed of 200 ms-1. What is the wavelength?
1.
i) Vibration is a kind of rapid to and fro motion of an object.
ii) This to and fro motion of the body causes the substances around it to vibrate.
2.
Loudness ∝ amplitude2
Amplitude ∝ \(\sqrt{Loudness} \)
Amplitude ∝ \(\sqrt{4} \)
Amplitude is increased by 2 times.
3.
| Music | Noise |
| Pleasant to the ear. | unpleasant to the ear. |
| Produced by the regular and periodic vibration | Produced by the irregular and non-periodic vibration |
4.
\(\mathrm{d}=2000 \mathrm{~m} \mathrm{t}=8 \mathrm{~s}\)
\(\mathrm{v}= distance/time =\mathrm{d} / \mathrm{t}\)
\(\mathrm{v}=2000 / 8=250\)
\(\mathrm{v}=250 \mathrm{~ms}^{-1}\)
5.
\(\mathrm{v} =200 \mathrm{~ms}^{-1} \quad \mathrm{n}=500 \mathrm{~Hz} \)
\(\mathrm{v} =\mathrm{n} \lambda \)
\(\lambda =\mathrm{v} / \mathrm{n} \)
\(=200 / 500=0.4 \)
\(\lambda =0.4 \mathrm{~m} \text { or } 40 \mathrm{~cm} \)
8th Standard Syllabus & Materials
8th Standard
Tamilnadu 8th Standard Social Science புவியியல் - புவிப்படங்களைக் கற்றறிதல் Important Questions And Answers Study Material - QB365
NEW8th Standard
Tamilnadu 8th Standard Social Science புவியியல் - கண்டங்களை ஆராய்தல் (ஆப்பிரிக்கா, ஆஸ்திரேலியா மற்றும் அண்டார்டிகா) Important Questions And Answers Study Material - QB365
NEW8th Standard
Tamilnadu 8th Standard Social Science புவியியல் - தொழிலகங்கள் Important Questions And Answers Study Material - QB365
NEW8th Standard
Tamilnadu 8th Standard Social Science வரலாறு - காலங்கள் தோறும் இந்தியப் பெண்களின் நிலை Important Questions And Answers Study Material - QB365
Tamilnadu Stateboard 8th Standard Subjects
Tamilnadu Stateboard Standards
