Physics - Study Mode

[#466] Which of the following is an example of continous emission spectrum?
Correct Answer

(A) Spectrum of an oil frame

Explanation

Solution: Spectrum of an oil frame is an example for continuous emission spectrum.

[#467] The atmospheric layer reflecting radio waves is called
Correct Answer

(B) Ionosphere

Explanation

Solution: The low-frequency end of the window is limited by signals being reflected by the ionosphere back into space, while the upper limit is caused by absorption of the radio waves by water vapour and carbon dioxide in the atmosphere.

[#468] For a ray of light to suffer total internal reflection it has to pass from :
Correct Answer

(C) Air to water

Explanation

Solution: Total internal reflection is an optical phenomenon that happens when a ray of light strikes a medium boundary at an angle larger than a particular critical angle with respect to the normal to the surface. This can only occur where light travels from a medium with a higher [n1=higher refractive index] to one with a lower refractive index [n2=lower refractive index]. Total internal reflection can be seen at the air-water boundary.

[#469] The unit of energy in MKS system is
Correct Answer

(A) Joule

Explanation

Solution: 1 Joule (J) is the MKS unit of energy, equal to the force of one Newton acting through one meter. 1 Watt is the power from a current of 1 Ampere flowing through 1 Volt.

[#470] One light year is equal to
Correct Answer

(B) 6 trillion miles

Explanation

Solution: One light year is equal to 5.88 trillion miles (6 trillion miles approx).