Modern Physics MCQs

1. Which of the following is the correct statement?

A. No photo electronic emission takes place if the frequency of radiation however intense it may be is less than a certain critical value called threshold frequency
B. Threshold frequency depends upon the nature of the metal surface
C. The maximum energy of a photoelectron is a function of frequency rather than intensity of radiation
D. All of the above
✅ The correct answer is option D.

2. Which of the following is NOT the correct statement?

A. A frame of reference which is either at rest or moves with a constant velocity is called an inertial frame of reference
B. An un-accelerated frame of reference is called an inertial frame of reference
C. All the frames of reference in uniform rectilinear motion are equivalent
D. Newtons laws of motion are valid in an accelerated (non-inertial) frame of reference
✅ The correct answer is option D.