Which of the following is not necessarily true about the image produced by a pinhole camera?  

A 90-kg man climbs up a flight of steps 5.5 m high in 30 s. What is the power developed by the man?

Which of the following is NOT a renewable source of energy?

In order to explain the nature of light using the experimental results known in his time, Neils Bohr came up with a theory called the complementarity principle. Which of the following is the best explanation of this principle?

The critical angle for total internal reflection is a:

When total internal reflection happens at a plastic-air interface 

The figure below shows two vibrating particles. What is the phase difference between the two particles?

Which of these statements is true for the image formed by spherical mirror? 

Speed of light in vacuum is 3.0 x 108 m/s. Speed of light in glass is 2.0 x 108 m/s. What is the refractive index of glass?

What happens when two waves meeting at a point are in phase?