NDA Science & Technology — practice questions
120 free MCQs with worked solutions. Tap any question for the answer + explanation, or practice them all in the app.
Practice NDA Science & Technology in the app →The Sanskrit text in which Acharya Kanada's atomic ideas are recorded is:The Greek word *atomos*, from which *atom* is derived, means:In which year did John Dalton propose his atomic theory based on scientific experiments?According to Dalton's atomic theory (1808):Who discovered the **electron** and in which year?In a cathode ray tube, the rays move from:Cathode rays are streams of:The charge of an electron, by convention, is:The actual magnitude of the charge of an electron in coulombs is approximately:J. J. Thomson received the Nobel Prize in Physics in:Thomson's model of the atom is also called the:In the watermelon analogy of Thomson's atomic model:The famous **gold foil experiment** was conducted in 1911 by:In the gold foil experiment, the particles aimed at the gold foil were:An alpha particle is identical to a nucleus of:Most alpha particles in the gold foil experiment:From the gold foil experiment, Rutherford concluded that the positive charge of an atom is:According to Rutherford's planetary model, electrons:The approximate diameter of an atom is:The approximate diameter of the nucleus is:If an atom were the size of a cricket ground (~100 m), the nucleus would be roughly the size of:Which scientific phenomenon, discovered in the late 19th century, demonstrated that atoms are NOT indivisible?J. J. Thomson worked at which famous laboratory in Cambridge?Why is Rutherford's atomic model called the **planetary model**?In Rutherford's atomic model, most of the mass of the atom is concentrated in:An atom is electrically neutral because:In Thomson's model, the colour of an atom (as shown in diagrams):The deflection of alpha particles from their straight path in the gold foil experiment is technically called:Conic sections find applications in:Sound is produced by:The object that produces sound is called the:In humans, sound is produced by the vibration of:A tuning fork is usually shaped like the letter:Sound needs a material medium to travel; it cannot propagate through:Sound waves in air are:A region of higher pressure (and density) in a sound wave is called a:A region of lower pressure (and density) in a sound wave is called a:The distance between two consecutive compressions (or two consecutive rarefactions) is the:The number of complete oscillations per second is called the:The SI unit of frequency is the:The time taken for one complete oscillation is the:If the frequency of a wave is f and its wavelength is λ, its speed v is given by:The maximum displacement of particles from their mean position is called the:The pitch of a sound is determined primarily by its:The loudness of a sound is related to its:The audible range of frequencies for a normal human ear is approximately:Sound of frequency above the human audible range is called:Sound of frequency below 20 Hz is called:Speed of sound is generally greatest in:At ordinary room temperature, the speed of sound in air is approximately:The speed of sound in a gas increases when:The reflection of sound from a distant obstacle that is heard distinctly after the original is called:The persistence of sound in a hall due to repeated reflections is called:For a clear echo, the minimum time gap between the original and reflected sound must be about:Using v ≈ 340 m/s in air, the minimum distance to a reflecting wall for a clear echo (sound goes and returns iBats locate prey in the dark mainly using:SONAR uses sound waves of which type for locating underwater objects?In SONAR, the depth of a sea bed is calculated using:Energy can change forms; when a tuning fork vibrates in air it converts mechanical energy mainly into:If a force F acts on an object that is displaced by s in the direction of the force, the work done is:The SI unit of work is the:If the displacement of an object is zero while a force acts on it, the work done by that force is:A force acts perpendicular to the displacement of an object. The work done by this force is:When the angle between force and displacement is obtuse (greater than 90°), the work done is:A man lifting a load against gravity does work that is:Energy is defined as the capacity to:The SI unit of energy is the same as that of:The energy possessed by a body due to its motion is called:The kinetic energy of an object of mass m moving with speed v is:If the speed of a body is doubled, its kinetic energy becomes:The energy possessed by a body by virtue of its position or configuration is called:The gravitational potential energy of an object of mass m at height h (near Earth's surface) is:A 2 kg ball is lifted to a height of 3 m. Taking g = 10 m/s², the gain in gravitational PE is:The kinetic energy of a 2 kg object moving at 5 m/s is:The law of conservation of energy states that energy can be:For a body falling freely under gravity (no air resistance), as it falls its kinetic energy:Power is defined as the:The SI unit of power is the:1 horsepower is approximately equal to:If 600 J of work is done in 30 s, the power developed is:1 kilowatt-hour (the commercial unit of electrical energy) equals:Mechanical advantage (MA) of a machine equals:For an ideal (frictionless) machine, the work output equals:The efficiency of a real machine is always:A lever in which the fulcrum lies between the load and the effort is a:Examples of simple machines include all of the following EXCEPT:A 50 N load is lifted by an ideal machine using an effort of 10 N. The mechanical advantage is:Consider the following pairs:
<table><tr><th>Plant</th><th>Description</th></tr><tr><td>I. Cassava</td><td>WooConsider the following types of vehicles :
I. Full battery electric vehicles
II. Hydrogen fuel cell vehicles
IWith reference to Unmanned Aerial Vehicles (UAVs), consider the following statements:
I. All types of UAVs canIn the context of electric vehicle batteries, consider the following elements:
I. Cobalt
II. Graphite
III. LitConsider the following substances:
I. Ethanol
II. Nitroglycerine
III. Urea
Coal gasification technology can beWhat is the common characteristic of the chemical substances generally known as CL-20, HMX and LLM-105, which Consider the following statements :
I. It is expected that Majorana 1 chip will enable quantum computing.
II. With reference to monoclonal antibodies, often mentioned in news, consider the following statements:
I. They aConsider the following statements:
I. No virus can survive in ocean waters.
II. No virus can infect bacteria.
Consider the following countries:
I. United Arab Emirates
II. France
III. Germany
IV. Singapore
V. Bangladesh
Consider the following statements :
Statement I :
Some rare earth elements are used in the manufacture of flatConsider the following statements :
I. Indian Railways have prepared a National Rail Plan (NRP) to create a 'fConsider the following space missions :
I. Axiom-4
II. SpaDeX
III. Gaganyaan
How many of the space missions giWith reference to India's defence, consider the following pairs :
<table><tr><th>Aircraft type</th><th>DescripGPS-Aided Geo Augmented Navigation (GAGAN) uses a system of ground stations to provide necessary augmentation.Consider the following plants:
1. Groundnut
2. Horse-gram
3. Soybean
How many of the above belong to the pea fThe organisms "Cicada, Froghopper and Pond skater" are :With reference to radioisotope thermoelectric generators (RTGs), consider the following statements:
1. RTGs arConsider the following statements:
Statement-I:
Giant stars live much longer than dwarf stars.
Statement-II:
CWhich one of the following is synthesised in human body that dilates blood vessels and increases blood flow?Consider the following activities:
1. Identification of narcotics on passengers at airports or in aircraft
2. Consider the following aircraft:
1. Rafael
2. MiG-29
3. Tejas MK-1
How many of the above are considered fifth In which of the following are hydrogels used ?
1. Controlled drug delivery in patients
2. Mobile air-condition“Membrane Bioreactors” are often discussed in the context of :Which one of the following words/phrases is most appropriately used to denote "an interoperable network of 3D Consider the following statements:
Statement-I:
India, despite having uranium deposits, depends on coal for moWhich of the following organisms perform waggle dance for others of their kin to indicate the direction and thConsider the following statements:
1. Some mushrooms have medicinal properties.
2. Some mushrooms have psychoaConsider the following statements :
1. Some microorganisms can grow in environments with temperature above theConsider the following actions:
1. Detection of car crash/collision which results in the deployment of airbagsConsider the following pairs :
<table><tr><th>Objects in space</th><th>Description</th></tr><tr><td>1. CepheidWhich one of the following countries has its own Satellite Navigation System?Consider the following statements :
1. Ballistic missiles are jet-propelled at subsonic speeds throughout thei