Physics Past Questions and Answers

X-rays and infrared rays are both electromagnetic. Which common property do the waves have? Both waves

A Are longitudinal
B Have same frequency
C Have the same wavelength
D Travel at the same speed in a vacuum

Question 1732:

The image formed by a concave mirror is real, inverted and magnified, when object is placed

A At the focus
B At the centre of curvature
C Beyond the centre of curvature
D Between the centre of curvature and the focus

Question 1733:

Total internal reflection. i. is a phenomenon of refraction of light. ii. occurs when light rays travel into a denser medium. iii. occurs when the critical angle is just exceeded. iv. is a phenomenon of reflection of light. Which of the statements above are correct?

A I and ii only
B I and iii only
C I, ii and iii only
D I, iii and iv only

Question 1734:

Complementary colours are those which

A Have the same refractive index
B Have the same wavelength
C Add-up to produce black light
D Add-up to produce white light

Question 1735:

The diagram given illustrates the waveform of a note produced by vibrations in an air column of length L. If the speed of sound in air is V, derive an expression for the frequency of the notes

A \(\frac{V}{L}\)
B \(\frac{5VL}{2}\)
C \(\frac{5L}{4V}\)
D \(\frac{5V}{4L}\)