21 January Morning Shift physics questions with solutions

Showing 1–10 of 25 questions

• MCQmediumCapacitorCapacitors with Dielectrics

  A parallel plate capacitor has capacitance C, when there is vacuum within the parallel plates.

  A sheet having thickness ( 1 ─── 3 )rd of the separation between the plates and relative permittivity K is introduced between the plates. The new capacitance of the system is :

  Options

  • Option A

    3KC /2K + 1

  • Option B

    CK / 2 + K

  • Option C

    3CK² /(2K + 1)²

  • Option D

    4KC /3K - 1

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• MCQmediumUnits, Dimensions, Measurements and ErrorsDimensional Analysis and Its Applications

  Consider a modified Bernoulli equation.

  P + A ───── Bt² + ρg(h + Bt) + ½ρV² = constant

  If t has the dimension of time then the dimensions of A and B are _____, _____respectively.

  Options

  • Option A

    [ML⁰T⁻¹] and [M⁰LT]

  • Option B

    [ML⁰T⁻¹] and [M⁰LT⁻¹]

  • Option C

    [ML⁰T⁻²] and [M⁰LT⁻²]

  • Option D

    [ML⁰T⁻²] and [M⁰LT⁻¹]

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• MCQeasyUnits, Dimensions, Measurements and ErrorsErrors in Measurement and Error Propagation

  In an experiment the values of two spring constants were measured as k₁ = (10 ± 0.2) N·m⁻¹ and k₂ = (20 ± 0.3) N·m⁻¹. If these springs are connected in parallel, then the percentage error in equivalent spring constant is :

  Options

  • Option A

    2.67%

  • Option B

    2.33%

  • Option C

    1.33%

  • Option D

    1.67%

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• MCQmediumNewtons law of motion and FrictionNewton's Second Law & Applications

  A 4 kg mass moves under the influence of a force $\vec{F}$= (4t³î - 3tĵ) N where t is the time in second.

  If mass starts from origin at t = 0, the velocity and position after t = 2s will be :

  Options

  • Option A

    $\vec{v}$ = 3î + 3 /2ĵ , $\vec{r}$= 6/5 î + ĵ

  • Option B

    $\overrightarrow{v}$= 4î - 3 /2 ĵ , $\vec{r}$= 8/5 î - ĵ

  • Option C

    $\vec{v}$= 4î + 5 / 2 ĵ , $\vec{r}$= 8/5 î + 2ĵ

  • Option D

    $\vec{v}$= 4î - 3 /2 ĵ, $\vec{r}$ = 6/5 î - ĵ

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• MCQmediumWave OpticsYoung's Double-Slit Experiment (YDSE)

  In a double slit experiment the distance between the slits is 0.1 cm and the screen is placed at 50 cm from the slits plane. When one slit is covered with a transparent sheet having thickness t and refractive index n(= 1.5), the central fringe shifts by 0.2 cm. The value of t is ____ cm.

  Options

  • Option A

    8 × 10⁻⁴

  • Option B

    6.0 × 10⁻³

  • Option C

    5.6 × 10⁻⁴

  • Option D

    5.0 × 10⁻³

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• NumericmediumGeometrical opticsLenses, Lens Combinations & Silvered Lenses

  A collimated beam of light of diameter 2 mm is propagating along x-axis. The beam is required to be expanded in a collimated beam of diameter 14 mm using a system of two convex lenses. If first lens has focal length 40 mm, then the focal length of second lens is ______________ mm.

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• NumericmediumRotational MotionMoment of Inertia & Rotational Kinetic Energy

  Two identical thin rods of mass M kg and length L m are connected as shown in figure. Moment of inertia of the combined rod system about an axis passing through point P and perpendicular to the plane of the rods is

  x ─── 2 ML² kg m².

  The value of x is __________.

  

  Your answer

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• MCQmediumPhotoelectric effect and dual naturePhotoelectric Effect & Einstein's Equation

  A light wave described by E = 60[sin(3 × 10¹⁵t) + sin(12 × 10¹⁵t)] (in SI units) falls on a metal surface of work function 2.8 eV. The maximum kinetic energy of ejected photoelectron is (approximately) _________ eV. (h = 6.6 × 10⁻³⁴ J·s. and e = 1.6 × 10⁻¹⁹C)

  Options

  • Option A

    5.1

  • Option B

    3.8

  • Option C

    6.0

  • Option D

    7.8

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• MCQmediumElectrostaticElectric Potential & Potential Energy

  A point charge of 10⁻⁸ C is placed at origin. The work done in moving a point charge 2 μC from point A(4, 4, 2) m to B(2, 2, 1) m is __________J.

  ( 1 ────── 4πε₀ = 9 × 10⁹ in SI units)

  Options

  • Option A

    45 × 10⁻⁶

  • Option B

    0

  • Option C

    30 × 10⁻⁶

  • Option D

    15 × 10⁻⁶

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• MCQmediumWork , Power and EnergyConservative Forces & Potential Energy

  Potential energy (V) versus distance (x) is given by the graph, Rank various regions as per the magnitudes of the force (F) acting on a particle from high to low.

  

  Options

  • Option A

    F₍ʙᴄ₎ > F₍ᴄᴅ₎ > F₍ᴅᴇ₎ > F₍ᴀʙ₎

  • Option B

    F₍ᴄᴅ₎ > F₍ᴀʙ₎ > F₍ʙᴄ₎ > F₍ᴅᴇ₎

  • Option C

    F₍ᴄᴅ₎ > F₍ᴅᴇ₎ > F₍ᴀʙ₎ > F₍ʙᴄ₎

  • Option D

    F₍ʙᴄ₎ > F₍ᴀʙ₎ > F₍ᴅᴇ₎ > F₍ᴄᴅ₎

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