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: B. along the tangent
Linear velocity of a particle moving in a circle is a vector directed along the geometric tangent. At any instant, the circular path direction matches the straight tangent line passing through that point. Centripetal acc...
Answer: B. radian
A radian is a dimensionless unit used exclusively to measure plane angles in geometry and trigonometry. Light years, angstroms, and microns are all well-established standard units of physical length. Comparing dimensions...
Answer: D. over heating
An electrical fuse is placed in series to melt and break the circuit when excessive current causes overheating. Connecting the fuse in series ensures that the entire circuit current flows through it. When current exceeds...
Answer: A. Drag force of air
Swinging pendulums encounter air molecules that exert resistive frictional forces against motion. This continuous aerodynamic drag removes mechanical energy from the oscillating pendulum system. Gradual energy loss cause...
Answer: A. at2/2
An object starting from rest with constant acceleration covers a distance given by basic kinematics. Integrating velocity over time yields the standard displacement formula s equals one half a t squared. The initial velo...
Answer: B. an apparent decrease in frequency
Sound waves emitted by a moving source get stretched out behind the traveling object. Longer wavelengths correspond directly to lower frequencies perceived by any stationary observer nearby. This phenomenon is a direct m...
Answer: B. Positron
A positron is classified as the antimatter counterpart of the ordinary subatomic electron. It possesses the exact same rest mass as an electron measured in physics laboratories. Unlike the negative electron, a positron c...
Answer: A. The shinning side of the ball
Laminar flow over the shiny side creates pressure differentials causing reverse swing. The shining side remains smooth, generating different aerodynamic forces than rough surfaces. Reverse swing forces the cricket ball t...
Answer: A. power
The scalar dot product of force and velocity yields mechanical power (P equals F dot v). Multiplying the magnitude of an applied force by the velocity component acting in the same direction calculates work done per unit...
Answer: A. friction
Frictional force dissipates mechanical energy by converting kinetic energy into thermal heat energy. The work done by friction depends heavily on the specific path taken between two points. Forces whose work depends on t...
Answer: D. directly proportional to B
The radius of a charged particle's circular path in a magnetic field is directly proportional to magnetic field parameters. Lorentz force equations dictate how magnetic fields bend moving charges into circular trajectori...
Answer: B. Wave property
Crystal diffraction experiments demonstrate the wave properties of particles. Davisson and Germer proved electrons and protons exhibit de Broglie wavelengths. Interference patterns confirm wave behavior for massive subat...
Answer: C. Venturi effect
The Venturi effect describes fluid pressure drops inside constricted pipe sections. Continuity equations dictate that flow velocity must increase through narrower pipe constrictions. Bernoulli's principle explains that h...
Answer: B. Wilson Cloud Detector
Wilson cloud chambers utilize supersaturated vapor to reveal invisible particle paths. Passing radiation ionizes gas molecules along its trajectory in the chamber. Condensation droplets form instantly around these ions,...
Answer: C. 180°
Light reflecting off a denser medium boundary undergoes a 180 degree phase shift. This inversion corresponds to a half-cycle delay in the reflected wave's oscillation. Boundary conditions at the interface mandate this ph...
