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. Steel
Elastic modulus measures a material resistance to being elastically deformed when a stress is applied to it. Steel possesses an exceptionally high Young modulus compared to common structural metals and soft polymers. Thi...
Answer: B. Linear accelerator
Linear accelerators employ synchronized oscillating electric fields to impart high velocities to charged particles. Charged atomic nuclei experience continuous electrostatic acceleration as they pass through consecutive...
Answer: A. Ne only
In a Helium-Neon laser, population inversion and subsequent laser emission occur exclusively in the Neon atoms. Helium atoms serve an auxiliary role by absorbing electrical energy and colliding with Neon atoms. Thus, las...
Answer: C. Maximum only
Resonance occurs when a driven system absorbs the maximum amount of energy from an external force. Energy transfer peaks when the driving frequency matches the natural frequency of the physical system. Maximum amplitude...
Answer: A. 5m/s, 1m/s
Let the two individual speeds be represented by u and v moving in opposite directions. When approaching each other, their relative speed of separation reduction is their sum, u plus v equals six. When moving in the same...
Answer: B. Non-inertial frame
An artificial satellite orbiting Earth accelerates towards the center, making it a non-inertial reference frame. Because the satellite experiences centripetal acceleration, Newton's laws require fictitious forces inside....
Answer: C. The angle of scattering is 180°
The Compton wavelength shift depends on the scattering angle through the cosine term in the numerator. When the scattering angle reaches one hundred eighty degrees, the cosine of that angle equals negative one. Subtracti...
Answer: A. 40
The Fahrenheit and Celsius temperature scales intersect and show the exact same numerical value at -40 degrees.
Answer: A. a gas filled ballon
A gas-filled balloon experiences significant upward buoyant forces from the surrounding atmospheric air. True projectile motion assumes the only acting force on the object is downward gravity. Buoyancy and aerodynamic li...
Answer: C. frequency lower than 20 Hz
The frequency of a simple pendulum is independent of its mass, but specific options reflect general wave properties.
Answer: C. The complete cycle of input A.C.
Full-wave rectifiers utilize diode bridge configurations to redirect alternating current phases. Both positive and negative input halves are inverted to flow in one uniform direction. A pulsating direct current output is...
Answer: D. All positions during SHM
Simple harmonic motion involves continuous energy interconversion between kinetic and potential forms. Total mechanical energy is the sum of kinetic and potential energies at any specific instant. Since friction is absen...
Answer: C. water
Optical activity requires molecules to possess a chiral asymmetry that rotates plane polarized light. Pure water molecules have a symmetric structure that lacks optical chirality. As a result, light passing through pure...
Answer: A. 2.0 mA
Ohm law relates maximum voltage and internal resistance to determine the safe operating current limit. Dividing the full-scale voltage of one hundred millivolts by the resistance of fifty ohms yields the result. The resu...
Answer: B. The positive half cycle of A.C.
Half wave rectifiers allow current passage during only one alternating cycle half. Positive half cycles pass through the diode while negative halves are blocked. Output direct voltage is delivered for exactly half of the...
