# Modern Physics MCQs

For your better entry test preparation and better Physics MCQs preparation, in this section, we are going to post Modern Physics MCQs.

Modern physics is the post-Newtonian conception of Physics. It implies that classical descriptions of phenomena are lacking and that an accurate and modern description of nature requires theories to incorporate elements of quantum mechanics or Einsteinian relativity or both.

### Modern Physics MCQs

1. Which of the following is the correct statement?
A. The flight path of a vertically falling body appears straight to the stationary observer
B. The flight path of the vertically falling body appears parabolic to an observer in uniform relative motion
C. All states of rest and motion are relative and there is no such thing as absolute motion
D. All the above

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

3. The relativistic energy E is equivalent to a relativistic mass given by
A. Ec2
B. E/c2
C. E/c
D. c2/E

4. An observer shoots parallel to a meter stick at very high (relativistic) speed and finds that the length of the meter stick is
A. Greater than one meter
B. Less than one meter
C. One meter
D. A foolish question

5. 0.001 kg mass will be equivalent to
A. 2.50 GWh
B. 25.00 GWh
C. 0.26 GWh
D. 250 GWh

6. Which one of the following radiations has the strongest photon?
A. T.V waves
B. Microwaves
C. X-rays
D. γ-rays

7. 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

8. The linear momentum of a photon is
A. Zero
B. Hv/c2
C. Hv/c
D. c2/hv

9. A device based on photoelectric effect is called
A. Photosensitive detection
B. Photo diode
C. Photosynthesis
D. Photocell

10. The linear momentum of an X-ray photon of wavelength 0.1A is
A. 6.625x1023N-s
B. 66.25x1023N-s
C. 662.5x1023N-s
D. Data is insufficient