All Free Everyday Science MCQs with Answers

1821. Vacuum tubes have been replaced by__________?

• A. Conductors
• B. Diodes
• C. Transistors
• D. None of these

Explanation: Transistors replaced bulky, fragile vacuum tubes because they are smaller, more reliable, require less power and produce less heat. Diodes are semiconductor components but are not the general replacement referred to here.

1822. One of the following countries produces maximum energy from atomic reactors?

• A. France
• B. USA
• C. UK
• D. none

Explanation: The United States has generally produced the greatest total amount of nuclear-generated electricity because it operates a large nuclear reactor fleet. France often leads in the percentage of its electricity supplied by nuclear power, which is a different comparison.

1823. Basha Dam is to be constructed on___________?

• A. River Sutlaj
• B. River Jhelum
• C. River Chenab
• D. None (On Indus River in Gilgit-Baltistan)

Explanation: The Diamer-Bhasha Dam is planned on the Indus River in Gilgit-Baltistan, not on the Sutlej, Jhelum or Chenab. Therefore, the stated 'None' option is correct.

1824. What is 'Stealth Technology'?

• A. A device which when attached to an aircraft makes it invisible on the radar
• B. A coating which reduces the visibility of an aircraft on radar
• C. A Technology by which it is possible for the aircraft's to spy in the enemy air-space
• D. A technology by using which paratroopers can be dropped stealthily behind the enemy columns.

Explanation: Stealth technology reduces an aircraft's radar signature through shaping, radar-absorbing materials and other design measures. A special coating can contribute to this reduction, but stealth is not simply a device that makes an aircraft completely invisible.

1825. A nuclear reactor is a device used to carry out controlled nuclear reaction whereas GM counter is a device used to detect?

• A. Current
• B. Voltage
• C. Nuclear Radiation
• D. power
• E. None of these

Explanation: A Geiger-Müller counter detects ionising nuclear radiation such as alpha, beta and gamma radiation. It does not measure ordinary electrical quantities like current or voltage.

1826. In a fission nuclear reaction , a heavy nucleus breaks up into smaller nuclei whereas in another nuclear reaction two or more than two possibly nuclei are fused to form a heavy nucleus This nuclear reaction is called ?

• A. Chemical Reaction
• B. Nuclear reaction
• C. Fission nuclear reaction
• D. Fusion nuclear reaction
• E. None of these

Explanation: Nuclear fusion joins two or more light nuclei to form a heavier nucleus and releases energy. Fission is the opposite process, in which a heavy nucleus splits into smaller nuclei.

1827. A moderator is used in nuclear reactor in order to ?

• A. Accelerate the neutrons
• B. Slow down the speed of the neutrons
• C. Increase the number of elections
• D. Decrease the number of electrons
• E. None of these

Explanation: A moderator reduces the speed of fast neutrons, commonly using materials such as water or graphite. Slow neutrons are more effective at sustaining fission in many nuclear reactors.

1828. Fuel used in a Fast Breeder Reactor is _____________?

• A. Uranium Oxide
• B. Uranium Plutonium carbide
• C. Uranium Plutonium Oxide
• D. Uranium thorium Oxide
• E. None of these

Explanation: Fast breeder reactors commonly use mixed uranium-plutonium oxide fuel, called MOX fuel. The reactor also converts fertile uranium-238 into additional plutonium fuel.

1829. Basic metals can be converted into gold by ?

• A. Heating
• B. Beating
• C. Artificial nuclear radioactivity
• D. Chemical reaction

Explanation: Changing one element into another requires nuclear transmutation, which changes the atomic nucleus and hence the atomic number. Heating and chemical reactions only alter physical state or chemical combinations, not one element into gold.

1830. Radioactive isotope of Uranium used in Nuclear Bomb is ?

• A. 92 U 235
• B. 92 U 234
• C. 92 U 233
• D. 92 U 238

Explanation: Uranium-235 is fissile, meaning it can sustain a rapid chain reaction with slow neutrons and is therefore used in nuclear weapons. Uranium-238 is abundant but not readily fissioned by slow neutrons.