ECAT Pre General Science Chapter 19 online mcq test with answers for Physics chapter 19 (Dawn of Modern Physics)

Question # 1

The location and speed anywhere on earth can now be determined using relativistic effects by NAVISTAR to an accuracy of

2 cm/s A
20 cm/s B
200 cm/s C
2000 cm/s D

Question # 2

When platinum wire is heated, it appears cherry red at

1600°C A
900°C B
1100°C C
1300°C D

Question # 3

An electron is accelerated through a potential difference of 50v. its de-Brogile wavelength is

1.66 x 10^-29m A
1.74 x 10^-10cm B
17.4 x 10^-6m C
1.74 x 10^-10m D

Question # 4

The general theory of relativity treats problems involving

inertial frame of references A
accelerating frame of references B
both of these C
none of these D

Question # 5

de-Broglies hypthesis was experimentally verified by

Maxwell A
Compton B
Einstein C
Davison and Germer D

Question # 6

From the theory of relativity, momentum p of the photon is related to energy as

p = hfc A
p = hf/c B
p = f(hc,f) C
p = cf/h D

Question # 7

The threshold frequency of sodium is 6 x 10⁶MHz. The cut-off wavelength for this metal will be

500 m A
500 nm B
500 km C
500 cm D
None of these E

Question # 8

Which of the following phenomenon proves the particle nature of light

interference A
diffraction B
photoelectric effect C
none of these D

Question # 9

Momentum is a parameter associated with

wave motion A
particle motion B
neither wave nor particle motion C
none of these D

Question # 10

If the radius of first orbit of hydrogen atom is 0.53° A the radius of second orbit will be

2.120°A A
0.212°A B
21.2°A C
0.14°
a
D

Question # 11

As the light shines on the metal surface, the electrons are ejected

slowly A
instantaneously B
either of these C
none of these D

Question # 12

The analysis of the distribution of wavelengths of the radiation emitted from a hot body set the foundation of new mechanics, known as

classical mechanics A
Newtonian mechanics B
quantum mechanics C
statistical mechanics D

Question # 13

In process of annihilation of matter, the two photons produced move in opposite direction to converse

momentum A
charge B
energy C
mass D

Question # 14

At the temperature, a body emits radiation which is principally

of long wavelengths in the visible region A
of long wavelengths in the invisible infrared region B
of short wavelength in invisible ultraviolet region C
none of these D

Question # 15

According to the electromagnetic wave theory of light, increasing the intensity of incident light should increase the

number of photoelectrons A
size of the photoelectrons B
charge on photoelectrons C
K.E of photoelectrons D

Question # 16

The special theory of relativity is based on:

Four postulates A
Three postulates B
Two postulates C
One postulate D
None of these E

Question # 17

The value of the plank's constant 'h' is given by

1.6 x 10^-19J A
1.67 x 10^-27Kg B
6.63 x 10³⁴Js C
6.63 x 10^-34Js D

Question # 18

Compton shift refers to:

Photon A
Meson B
Proton C
Positron D
Both (B) and (D) E

Question # 19

The existence of position was predicted by Dirace in

1920 A
1925 B
1930 C
1928 D

Question # 20

The Einstein's changes in length, mass and time are not observed in common life because

We dont observer then seriously A
The masses are too large B
Their speed is too small than the speed of right C
All of the above D

Question # 21

With the help of 50 K v electron microscope, a resolution of

0.5 to 1 m to possible A
1 m to 10 m is possible B
0.5 to 1 nm is possible C
1 to 10 nm is possible D

Question # 22

The intensity of emitted energy (with wavelength) radiated from a black body at different temperatures was initially measured by:

Lummer A
Planck B
Pringsheim C
Both (A ) and (B) D
Both (A) and (C) E

Question # 23

As compared to the distance measured by an observer on Earth, the distance from Earth to a star measured by an observer in a moving spaceship would seem:

Smaller A
Lerger B
Same C
Much larger D
None of these E

Question # 24

Max plank founded a mathematical model resulting in an equation that describes the shape of observed black body radiation curves exactly, in

1890 A
1895 B
1900 C
1905 D

Question # 25

The year when A.H. compton was awarded Nobel Prize is:

1923 A
1927 B
1931 C
1935 D
None of these E

Question # 26

The unit of work function is:

Joule A
Electron volt B
That of threshold frequency C
Both (A) and (B) D
None of these E

Question # 27

When a platinum wire is heated, it appears yellow at

1600°C A
900°C B
1100°C C
1300°C D

Question # 28

The special theory of relatively treats the problems involving:

Inertial frames of reference A
Non-inertial frames B
Non-accelerated frame C
Botha (A) and (C) D
Both (B) and (C) E

Question # 29

Position and momentum of a particle cannot both be measured simultaneously with perfect accuracy. This is the statement of

photoelectric effect A
pair production B
Compton effect C
uncertainty principle D

Question # 30

According to the special theory of relativity, time is

absolute quantity A
not absolute quantity B
constant quantity C
none of these D

Sr.#	Question	Answer
1	Max plank founded a mathematical model resulting in an equation that describes the shape of observed black body radiation curves exactly, in	A. 1890 B. 1895 C. 1900 D. 1905
2	An intertial frame of reference is a frame of reference which is	A. at rest B. moving with uniform velocity C. either at rest or moving with uniform velocity D. none of these
3	Compton shift refers to:	A. Photon B. Meson C. Proton D. Positron
4	As the light shines on the metal surface, the electrons are ejected	A. slowly B. instantaneously C. either of these D. none of these
5	Absolute motion cannot be detected	A. in its own frame of references B. in a different frame of references C. both in its frame and different frame of references D. none of these
6	Intensity of light determines the:	A. Energy of each photon B. Number of photons C. Speed of photons D. Size of photons
7	Which of the following is not an example of intertial frame	A. a body placed on the surface of earth B. a body placed in a car moving with uniform velocity C. a body placed in a car moving with same acceleration D. none of these
8	The year when A.H. compton was awarded Nobel Prize is:	A. 1923 B. 1927 C. 1931 D. 1935
9	The mass 'm' of a body moving at 0.8 c (whose rest mass is mo) becomes	A. 2 mo B. 1.67 mo C. 0.67 mo D. 2.67 mo
10	The special theory of relatively treats the problems involving:	A. Inertial frames of reference B. Non-inertial frames C. Non-accelerated frame D. Botha (A) and (C)

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ECAT Pre General Science Physics Chapter 19 MCQ Test With Answer

MCQ's Test For ECAT Pre General Science Physics Chapter 19 Dawn of Modern Physics

ECAT Pre General Science Physics Chapter 19 Dawn of Modern Physics