Which of the following types of light carries a signal from a television remote to the device it controls?
A. Polarised
B. Ultraviolet
C. Infrared
D. X-ray
Answer: Option C
A. Polarised
B. Ultraviolet
C. Infrared
D. X-ray
Answer: Option C
Which of the following substances will have the lowest speed of sound?
A. Water
B. Steel
C. Glasss
D. Air
What is the approximate range of sound for humans?
A. 20Hertz to 2000 Hertz
B. 20Hertz to 200Hertz
C. 20 Hertz to 20000 Hertz
D. 2 Hertz to 2000 Hertz
Loudness of sound depends upon which of the following?
A. Frequency
B. Wavelength
C. Amplitude
D. Overtones
A. On land
B. In air
C. In space
D. Underwater
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