Physics holds 894 questions with answers, free to read and with no account needed. They are grouped into 1 category: Physics.
Attempt each question before revealing the answer, and keep a note of the ones you get wrong — those are the topics worth reading about properly. If an answer looks wrong, there is a link to report it on every question.
Answer: A. The extension of the wire is proportional to the force applied
Hooke law establishes that extension in elastic materials is directly proportional to applied load forces. Internal elastic potential energy stored in stretched cords depends on the applied force and extension. Linear el...
Answer: C. shadow photograph
X-ray imaging passes penetrating radiation through different bodily tissues onto detectors. Dense bones absorb more X-rays while soft tissues allow radiation to pass through freely. This differential tissue absorption cr...
Answer: C. 0.1mm
The least count of a Vernier caliper with 10 divisions on the Vernier scale is 0.1 mm. Least count is calculated as the main scale division value minus the Vernier scale division value. Ten Vernier divisions matching nin...
Answer: C. a circle in a plane perpendicular to the field
A magnetic force always acts perpendicularly to the velocity of a moving charged particle. This constant perpendicular force provides the necessary centripetal force for circular motion. The resulting trajectory is a cir...
Answer: C. 0.75J
Stored elastic potential energy is calculated as 0.5 * F * delta_l or using Young's modulus formulas. Substituting the area, length, elongation, and Young's modulus into the energy formula gives the result. Calculating 0...
Answer: A. zero
Terminal potential difference evaluates to zero when short circuits eliminate voltage drops. No current flows through external loads during open switch or shorted conditions. Internal resistance and EMF balance out perfe...
Answer: B. 2.6×10⁶ m/s
Relativistic mass increase follows the specific equation incorporating the Lorentz factor for high velocity motion. Doubling the rest mass requires a velocity that produces a Lorentz factor equal to two. Substituting thi...
Answer: A. Conduction band
In solid conductors, the valence band overlaps with the conduction band, and the lowest energy band (valence band) is completely filled with electrons.
Answer: A. luminous
A luminous body generates its own visible light through internal physical or chemical processes. This generation distinguishes self-illuminating objects from those that merely reflect ambient light. The term luminous dir...
Answer: B. Diffraction
Light waves diffract around the edges of a spherical obstacle. Constructive interference at the exact center creates a bright spot. This classic optical phenomenon is known historically as Poisson spot. Diffraction cause...
Answer: C. 99.2 cm
A standard seconds pendulum is defined as having a complete period of precisely two seconds. Using the pendulum period formula and local gravity yields a calculated length near ninety nine point two centimeters. Precisio...
Answer: B. more heat is produced in thin wire
A thin wire possesses a much higher electrical resistance than a thick wire of equal length. According to Joules law, higher resistance directly translates into greater thermal energy generation during current flow. The...
Answer: B. Least count of the instrument
Absolute uncertainty of a direct physical measurement is typically determined by the least count of the measuring instrument. Instruments like rulers or micrometers have a minimum graduation that sets the limit of readin...
Answer: D. Both 1st and 3rd
The trigonometric tangent function represents the ratio of the sine function to the cosine function. In the first quadrant both sine and cosine are positive making their ratio strictly positive. In the third quadrant bot...
Answer: B. Monochromatic
Optical fiber communication systems require monochromatic light to avoid severe chromatic dispersion across long distances. Lasers provide this single frequency light, which ensures signals do not distort during transmis...
