All Free Physics MCQs with Answers

• A. Alpha radiation
• B. Beta radiation
• C. Gamma radiation
• D. X radiation

Explanation: Alpha radiations are doubly positively charged helium nuclei. When such radiation is emitted from a radioactive element, its mass number…

• A. one curie
• B. one Becquerel
• C. one half life
• D. all of these

Explanation: In radioactivity, activity is defined as disintegrations per second. The SI unit of Activity is Becquerel (Bq).

• A. Electron
• B. Positron
• C. Proton
• D. Neutron

Explanation: In the nuclear reaction 11Na24 → 12Mg24 + X, the atomic number increases by one, indicating a beta-minus decay.

• A. curie
• B. Becquerel
• C. Tesla
• D. both a and b

Explanation: The activity of a radioactive material, which represents the rate of decay of radioactive nuclei, can be expressed in units of both curie…

• A. 83Bi214
• B. 84Po214
• C. 82Pb214
• D. 41TI214

Explanation: In beta decay, a neutron in the nucleus is transformed into a proton and a beta particle (an electron) is emitted.

• A. Temperature
• B. Pressure
• C. Humidity level
• D. None of the above

Explanation: Radioactive decay is the process by which an unstable atomic nucleus loses energy by emitting radiation.

• A. 47Ag111
• B. 47Ag110
• C. 47Ag112
• D. 49In111

Explanation: In β⁻ emission (beta minus decay): An electron (β⁻ particle) is emitted.→ Atomic number increases by 1, mass number stays same.So the…

• A. α-particles
• B. electrons and neutrons
• C. Positron and neutrinos
• D. Only neutrons

Explanation: Nuclear fission is when heavy unstable nuclei disintegrate to two lighter nuclei along with the emission of a neutron, electron, and energy.

• A. Straight
• B. Erratic
• C. Circular
• D. Elliptical

Explanation: The path traced by beta particles in air is erratic. This is because beta particles are high-speed electrons emitted during radioactive…

• A. Decay constant
• B. Half life
• C. Mean life
• D. Activity

Explanation: The Becquerel (Bq) is the standard unit for measuring radioactivity, specifically the activity of a radioactive substance.

• A. 9
• B. 5
• C. 3
• D. 1

Explanation: To calculate the magnitude of a vector, we can use the formula:|A| = √(Ax² + Ay² + Az²Where 'A' is the vector and Ax, Ay, and Az are the…

• A. 45 degrees
• B. 135 degrees
• C. 225 degrees
• D. 315 degrees

Explanation: To find the angle subtended by a vector A with the x-axis, we can use the inverse tangent function.

• A. X_plate
• B. Y_plate
• C. Electron gun
• D. Accelerating electrode

Explanation: Accelerating electrode: This option is correct. The time base sweep circuit is connected to the accelerating electrode, which controls the…

• A. Summarizes its output
• B. Tabulates all its input conditions only
• C. Displays all its input/output possible
• D. Is not based on the logic algebra

Explanation: The truth table displays all the input/output possibilities for the logic function.

• A. NOT gate
• B. AND gate
• C. NAND gate
• D. OR gate

Explanation: A NOT gate, also known as an inverter, has one input and one output. The output of a NOT gate is always the opposite of the input.

• A. Rectification
• B. Amplification
• C. Oscillation
• D. Regeneration

Explanation: Rectification is the correct answer because it specifically refers to the conversion of alternating current (AC) into direct current (DC).

• A. Ohm
• B. Ohm-meter-1
• C. Ohm - meter
• D. mho

Explanation: The SI unit for conductance is siemen or mho. This is also written as 1/ohm or ohm-1.

• A. 25 ohm
• B. 50 ohm
• C. 75 ohm
• D. 100 ohm

Explanation: In a balanced Wheatstone bridge, the ratio of the resistances in one arm is equal to the ratio of the resistances in the other arm…

• A. Metallic conductor
• B. Transistors
• C. Diodes
• D. Electric arcs

Explanation: Ohm's law states that the current through a conductor between two points is directly proportional to the voltage across the two points…

• A. 100Ω
• B. 200Ω
• C. 50Ω
• D. 150Ω

Explanation: The resistance R of a wire is given by the formula: R = ρL/A, where ρ is the resistivity, L is the length, and A is the cross-sectional…