All Free Physics MCQs with Answers

• A. Increase.
• B. Completely diminishes.
• C. Reduces to half.
• D. Remains unchanged.

Explanation: The requirement for a photon to carry out pair production is a minimum energy level of 1.02 MeV, if the energy level increases the…

• A. Infrared.
• B. Ultraviolet.
• C. Visible.
• D. Green.

Explanation: In photocell cesium, coated oxidised silver cathode emits electrons for infrared light.

• A. Low
• B. High
• C. Intermediate
• D. Both A and C

Explanation: Energy will be emitted when electrons jump from higher energy levels to lower energy levels.

• A. hf - ϕ = ½ mv2
• B. E = hc2
• C. E = mc2
• D. hf = ½ mv2

Explanation: Explanation:Einstein's photoelectric equation states that the maximum energy of a photoelectron is equal to the difference between the…

• A. 1.43 x 10^-11 m
• B. 2.43 x 10^-12 m
• C. 2.56 x 10^-12 m
• D. 3.46 x 10^-6 m

Explanation: Explanation: This value is a constant and is given as: = h / moc = 6.63 × 10-23 / (9.1093837015 × 10-31kg) (3× 108 ms-1) = 2.43 × 10-12m

• A. Compton Effect
• B. Photoelectric Effect
• C. Nuclear Effect
• D. Pair Production

Explanation: Explanation:For intermediate energy of radiations, the dormant process is Compton effect. This option is not correct.

• A. High frequency
• B. Low frequency
• C. Threshold frequency
• D. Resonance frequency

Explanation: The correct answer is Threshold frequency. This is the minimum frequency of light necessary to eject electrons from a metal surface as…

• A. α-particle
• B. β-particle
• C. X-rays
• D. γ-radiations

Explanation: In pair production, a high-energy photon interacts with a nucleus to transform into a particle and its antiparticle, such as an electron…

• A. 2.00 x 10^16Hz
• B. 2.00 x 10^14 Hz
• C. 5.00 x 10^16Hz
• D. 2.00 x 10^18 Hz

Explanation: Where h is planck's constant whose value is 6.6x10^-34J.s = 6.6x10^-34/4.42x10^-26 =1.5x10^-8m Now finding frequency of photon: 𝞴xf=c c…

• A. Kg ms-2
• B. Kgm2s-2
• C. Kgm2s-3
• D. None of these

Explanation: According to Newton's 2nd lawF=maWhere F is force , m is mass and a is acceleration .

• A. Giga
• B. Tera
• C. Mega
• D. Deca

Explanation: The correct answer is Tera, as it represents 1012, the largest power of ten among the options.

• A. Ampere
• B. Volt
• C. Coulomb
• D. Calorie

Explanation: The correct answer is Coulomb, which is the SI unit used to measure electric charge.

• A. Am
• B. Js-1
• C. As
• D. C

Explanation: In terms of SI base units, 1 C is the equivalent of 1 ampere-second, which can be expressed as 1 C = 1 A ⋅ 1 s (or C = A ⋅ s).

• A. Base Quantities
• B. Physical Quantities
• C. Derived Quantities
• D. Supplementary Quantities

Explanation: Physical Quantities, by definition, are quantities that can be measured with the help of an instrument to give a numerical value with a…

• A. NOR.
• B. XNOR.
• C. XOR.
• D. Both B and C.

Explanation: In logic gates, a NAND gate produces an output of 1 unless both inputs are 1. For inputs A=0 and B=1, the NAND gate outputs 1.

• A. High voltage.
• B. Photon.
• C. Hole.
• D. Positron.

Explanation: A hole or an electron hole is a point in an atom, a lattice or a structure where an electron can exist but does not because it has been…

• A. No
• B. Very large
• C. Few milliamperes
• D. Both A and C

Explanation: a) No: This option suggests that practically no current flows in a reverse p-n junction.

• A. Indium
• B. Aluminium
• C. Arsenic
• D. Both B and C

Explanation: N- type semiconductor is denoted by positive ion and free electron.Silicon Si has 4 valence electrons and Arsenic As has 5 valence…

• A. -1
• B. 10
• C. -10
• D. 1

Explanation: Explanation:The gain of an inverting amplifier using an operational amplifier is given by the ratio of the feedback resistor to the input…

• A. AND Gate
• B. XNOR Gate
• C. NAND Gate
• D. NOR Gate

Explanation: Explanation:If inputs A = 1, B = 0, and output X = 1, the it corresponds to the operation of a NAND Gate.