41- Which of the following was discovered first in the chromosphere of the sun?
A. Xenon
B. Helium
C. Neon
D. Krypton
View Answer
Answer : B. Helium
Description
42- Which among the following is a positively charged particle emitted by a radioactive element?
A. Beta ray
B. Alpha particle
C. Gamma ray
D. Cathode ray
View Answer
Answer : B. Alpha particle
Description
43- Nuclear fission is caused by the impact of:
A. Proton
B. Electron
C. Neutron
D. None of these
View Answer
Answer : C. Neutron
Description
44- What is the correct ascending order for frequencies of the following radiations?
1. Visible radiations 2. X-rays 3. Ultraviolet radiations 4. Radio Waves
A. 1, 3, 2, 4
B. 3, 2, 4, 1
C. 4, 1, 3, 2
D. 4, 3, 1, 2
View Answer
Answer : C. 4, 1, 3, 2
Description
45- Which of the following is a good nuclear fuel?
A. Uranium-238
B. Neptunium-239
C. Thorium-236
D. Plutonium-239
View Answer
Answer : D. Plutonium-239
Description
46- Long distance photography is facilitated by:
A. X-ray
B. Visible light
C. Infrared rays
D. Ultraviolet rays
View Answer
Answer : C. Infrared rays
Description
47- The difference between a nuclear reactor and an atom bomb is that:
A. No chain reaction takes place in nuclear reactor while in the atomic bomb there is a chain reaction
B. No chain reaction takes place in atomic bomb while it takes place in a nuclear reactor
C. The chain reaction in nuclear reactor is controlled
D. None of these
View Answer
Answer : C. The chain reaction in nuclear reactor is controlled
Description
48- How many colours does the sunlight spectrum have?
A. Five
B. Three
C. Seven
D. Nine
View Answer
Answer : C. Seven
Description
49- What is the wavelength of visible spectrum?
A. 1300Å-3000Å
B. 3900Å-7600Å
C. 7800Å-8000Å
D. 8500Å-9800Å
View Answer
Answer : B. 3900Å-7600Å
Description
50- Which radioactive pollutant has recently drawn the attention of the public, due to its occurrence in the building material?
A. Radon
B. Radium
C. Thorium
D. Plutonium
View Answer
Answer : A. Radon
Description
51- In an atomic explosion, enormous energy is released which is due to the:
A. Conversion of mass into energy
B. Conversion of neutrons into protons
C. Conversion of chemical energy into heat energy
D. Conversion of mechanical energy into nuclear energy
View Answer
Answer : A. Conversion of mass into energy
Description
52- Which of the following types of photons has the highest energy?
A. X-rays
B. Visible
C. Radio waves
D. Gamma rays
View Answer
Answer : D. Gamma rays
Description
53- Atoms of an element differ from those of all other elements in:
A. Atomic number and number of valence electrons
B. Atomic number and electronic configuration
C. Number of neutrons and electronic configuration
D. None of these
View Answer
Answer : B. Atomic number and electronic configuration
Description
54- Which of the following is used as coolant in nuclear reactors?
A. Cadmium
B. Heavy water
C. Liquid sodium
D. Graphite
View Answer
Answer : B. Heavy water
Description
55- The isotope of uranium capable of sustaining chain reaction is:
A. U-235
B. U-238
C. U-239
D. None of these
View Answer
Answer : A. U-235
Description
56- Radioactive disintegration of uranium ultimately results in formation of:
A. Lead
B. Polonium
C. Thorium
D. Radium
View Answer
Answer : A. Lead
Description
57- Atom bomb is based on the principle of:
A. Nuclear fusion
B. Nuclear fission
C. Both A and B
D. None of the above
View Answer
Answer : B. Nuclear fission
Description
58- Which of the following statements are correctly associated with ultrasonic waves?
1. These are the acoustic waves of frequencies more than 20,000 Hertz.
2. When possible to use, these waves are preferred over X-rays for getting an image of internal organs because they are not harmful.
3. Their velocity is more than the velocity of sound.
A. 1 only
B. 1 and 2
C. 2 and 3
D. 1 and 3
View Answer
Answer : C. 2 and 3
Description
59- Which of the following has the least penetrating power?
A. Alpha particles
B. Beta particles
C. Gamma rays
D. All have the same penetrating power
View Answer
Answer : A. Alpha particles
Description
60- What is the increasing order of the wavelengths of the following colours?
1. Orange 2. Indigo 3. Yellow 4. Violet
