Which from the following is true for "Sound"?

22. Which from the following is true for "Sound"?

A. Sound cannot travel through a vaccum

B. Sound cannot travel through gases
C. Sound cannot travel through liquids
D. Sound cannot travel through solids

23. When white light is passed through a prism, it splits into __________ colours.

A. 5

B. 6

C. 7
D. 8

24. 1 nanometer = ? 

A. 10-3 meter
B. 10-6 meter

C. 10-9 meter

D. 10-12 meter

25. Instrument used for measuring very high temperature is _________.

A. Pyroscope

B. Pyrometer

C. Seismograph
D. Xylometer