Competitive Exams: Physics MCQs (Practice-Test 26 of 35)

  1. The given figure shows the waveforms for two inputs A and B and that for the output Y of a logic circuit. The logic circuit is

    1. an AND gate

    2. an OR gate

    3. a NAND gate

    4. an Exclusive OR gate

    • Assertion (A): p-n junction diodes can be used even at ultra high frequencies.
    • Reason (R): Capacitate reactance of a p-n junction diode increases as frequency increases.
    1. Both A and R are true and R is the correct explanation of A

    2. Both A and R are true but R is not a correct explanation of A

    3. A is true, but R is false

    4. A is false but R is true

    • Assertion (A): e/m of beta particles is not constant.
    • Reason (R): Velocities of beta particles are quite high and are comparable to the velocity of light.
    1. Both A and R are true and R is the correct explanation of A

    2. Both A and R are true but R is not a correct explanation of A

    3. A is true, but R is false

    4. A is false but R is true

    • Assertion (A): In Compton effect, the scattered photon has more energy than the incident photon.
    • Reason (R): Energy and momentum are conserved during the scattering of a photon by an electron.
    1. Both A and R are true and R is the correct explanation of A

    2. Both A and R are true but R is not a correct explanation of A

    3. A is true, but R is false

    4. A is false but R is true

    • Assertion (A): When a sound wave propagates through air, the displacements take place in the direction of propagation.
    • Reason (R): Sound waves can be polarized as in the case of light rays.
    1. Both A and R are true and R is the correct explanation of A

    2. Both A and R are true but R is not a correct explanation of A

    3. A is true, but R is false

    4. A is false but R is true

    • Assertion (A): A convex lens suffers from chromatic aberration.
    • Reason (R): All parallel rays passing through a convex lens do not come to a focus at the same point.
    1. Both A and R are true and R is the correct explanation of A

    2. Both A and R are true but R is not a correct explanation of A

    3. A is true, but R is false

    4. A is false but R is true