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🇮🇳 RRB Group D · flashcards
RRB Group D General Science - Physics Flashcards
51 question-and-answer cards covering General Science - Physics as it is examined in RRB Group D. 24 of them are printed below, taken from across the deck — no signup, no paywall on the preview.
24 sample cards from the General Science - Physics deck
Sampled from the end of the deck, so these are different cards from the ones shown on the syllabus page.
What is a simple machine, and what is its main purpose?
A simple machine is a basic mechanical device that changes the magnitude or direction of a force to make work easier. Examples: lever, pulley, inclined plane, wedge, screw, wheel and axle.
Define mechanical advantage of a machine.
Mechanical advantage (MA) is the ratio of load (output force) to effort (input force): MA = Load/Effort. It tells how many times a machine multiplies the effort.
What are the three classes of levers? Distinguish them by the position of the fulcrum, load, and effort.
Class 1: fulcrum between load and effort (e.g., seesaw, scissors). Class 2: load between fulcrum and effort (e.g., wheelbarrow, nutcracker). Class 3: effort between fulcrum and load (e.g., tongs, human forearm).
Why can no machine be 100% efficient?
Because some input energy is always lost to friction, heat, sound, etc., so the useful output energy is always less than the input energy; efficiency = (output/input) x 100% is always below 100%.
What is the difference between heat and temperature?
Heat is the total thermal energy transferred between bodies due to a temperature difference (measured in joules/calories). Temperature is the degree of hotness or coldness, a measure of average kinetic energy of particles (measured in kelvin/celsius).
What are the three modes of heat transfer? Briefly define each.
Conduction (heat transfer through direct particle contact, mainly in solids), convection (heat transfer by movement of fluid - liquids/gases), and radiation (heat transfer by electromagnetic waves, needing no medium).
Give the formula to convert Celsius to Fahrenheit and to Kelvin.
F = (9/5)C + 32; K = C + 273.15 (often taken as C + 273).
What is the boiling point and freezing point of water in Celsius and Kelvin at standard pressure?
Freezing point: 0 degrees C = 273.15 K; boiling point: 100 degrees C = 373.15 K.
What is latent heat?
Latent heat is the heat energy absorbed or released by a substance during a change of state (e.g., melting or boiling) at constant temperature, without a change in temperature.
State the laws of reflection of light.
1) The angle of incidence equals the angle of reflection. 2) The incident ray, the reflected ray, and the normal at the point of incidence all lie in the same plane.
What is refraction of light, and why does it occur?
Refraction is the bending of light as it passes from one transparent medium to another. It occurs because the speed of light changes when the medium changes (it bends toward the normal entering a denser medium and away when entering a rarer medium).
What type of image and use is associated with a concave mirror versus a convex mirror?
A concave mirror can form real or virtual, magnified images (used in shaving mirrors, headlights, dentists' mirrors). A convex mirror always forms a virtual, diminished, erect image with a wider field of view (used as rear-view/side mirrors in vehicles).
What is the difference between a convex (converging) lens and a concave (diverging) lens?
A convex lens is thicker at the centre and converges light to a focus (can form real images; used in magnifying glasses, cameras, to correct hypermetropia). A concave lens is thinner at the centre, diverges light, always forms a virtual erect diminished image (used to correct myopia).
What causes the dispersion of white light, and what are the seven colours of the spectrum in order?
Dispersion occurs because different colours bend by different amounts (different refractive indices) when passing through a prism. The order (VIBGYOR) is Violet, Indigo, Blue, Green, Yellow, Orange, Red.
Which defects of vision are corrected by concave and convex lenses respectively?
Myopia (short-sightedness) is corrected by a concave (diverging) lens; hypermetropia (long-sightedness) is corrected by a convex (converging) lens.
What is sound, and what kind of wave is it?
Sound is a form of energy produced by vibrating bodies that travels as a longitudinal mechanical wave, requiring a material medium (solid, liquid, or gas) to propagate; it cannot travel through a vacuum.
In which medium does sound travel fastest - solids, liquids, or gases - and why?
Sound travels fastest in solids (slowest in gases) because particles are packed most closely in solids, allowing vibrations to be transmitted more quickly.
What is the approximate speed of sound in air at room temperature?
About 343 m/s (commonly taken as around 340 m/s) at about 20 degrees C; it increases with temperature.
What is an echo, and what is the minimum distance needed to hear one?
An echo is the repetition of a sound caused by reflection of sound waves from a surface. To hear a distinct echo, the reflecting surface must be at least about 17 metres away (so the time gap is at least 0.1 second).
What are the audible, infrasonic, and ultrasonic frequency ranges for the human ear?
Audible range: 20 Hz to 20,000 Hz (20 kHz). Infrasonic: below 20 Hz. Ultrasonic: above 20,000 Hz.
State Ohm's law and give its formula.
Ohm's law states that, at constant temperature, the current through a conductor is directly proportional to the potential difference across it: V = IR (voltage = current x resistance).
State the SI units of electric current, potential difference (voltage), and resistance.
Current: ampere (A); potential difference/voltage: volt (V); resistance: ohm (omega).
How do total resistance and current behave in a series circuit versus a parallel circuit?
In series: resistances add (R = R1 + R2 + ...), the same current flows through all components, and total resistance increases. In parallel: 1/R = 1/R1 + 1/R2 + ..., voltage is the same across each branch, total resistance decreases, and total current is the sum of branch currents.
State the formulas for electrical power and the heat produced by current (Joule's heating effect).
Electrical power: P = VI = I^2R = V^2/R. Heat produced (Joule's law of heating): H = I^2Rt, where I = current, R = resistance, t = time.
What this deck covers
The General Science - Physics deck follows the RRB Group D General Science - Physics syllabus — 4 chapters and 13 topics — so questions land on material that is genuinely examinable rather than trivia around it. That works out to roughly 12.8 cards per chapter.
Answers are written to be recallable, not just readable — averaging about 179 characters, which is long enough to carry the reasoning and short enough to say out loud.
A deck like this earns its keep on the second and third pass. Read the syllabus first so you know the shape of the subject, then use the cards to find the specific facts that have not stuck.
General Science - Physics flashcards FAQ
How many General Science - Physics flashcards are in this RRB Group D deck?
51 cards. This page previews 24 of them, sampled evenly across the deck so you can judge the difficulty before installing anything.
Are these RRB Group D flashcards free?
Yes. The preview here is free to read with no signup, and the full 51-card deck is free inside the Examius app.
What do the General Science - Physics cards cover?
They follow the RRB Group D General Science - Physics syllabus — 4 chapters and 13 topics — so the questions track what is actually examinable.
How should I use these flashcards?
Read the syllabus first so you know the shape of the subject, then drill the deck. Examius schedules each card with spaced repetition, so cards you keep missing come back sooner and ones you know drift further apart.