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JEE Main 2024 Jan 30 Shift 1 — Physics

30 questions Ā· 30 with the official NTA answer

Q31JEE Main 2024 Jan 30 Shift 1Units and MeasurementsEasy

Match List - I with List - II.

List - I List - II
(A) Coefficient of viscosity (I) [M L2 Tāˆ’2][\mathrm{M\,L^2\,T^{-2}}]
(B) Surface tension (II) [M L2 Tāˆ’1][\mathrm{M\,L^2\,T^{-1}}]
(C) Angular momentum (III) [M Lāˆ’1 Tāˆ’1][\mathrm{M\,L^{-1}\,T^{-1}}]
(D) Rotational kinetic energy (IV) [M L0 Tāˆ’2][\mathrm{M\,L^0\,T^{-2}}]

Choose the correct answer from the options given below :

  1. A

    (A)-(I), (B)-(II), (C)-(III), (D)-(IV)

  2. B

    (A)-(III), (B)-(IV), (C)-(II), (D)-(I)

  3. C

    (A)-(II), (B)-(I), (C)-(IV), (D)-(III)

  4. D

    (A)-(IV), (B)-(III), (C)-(II), (D)-(I)

Show answer

Correct option: B

Q32JEE Main 2024 Jan 30 Shift 1Rotational MotionMedium

A particle of mass m is projected with a velocity 'u' making an angle of 30°30° with the horizontal. The magnitude of angular momentum of the projectile about the point of projection when the particle is at its maximum height h is :

  1. A

    32 mu2g\frac{\sqrt{3}}{2}\,\frac{\mathrm{mu}^2}{\mathrm{g}}

  2. B

    zero

  3. C

    316 mu3g\frac{\sqrt{3}}{16}\,\frac{\mathrm{mu}^3}{\mathrm{g}}

  4. D

    mu32 g\frac{\mathrm{mu}^3}{\sqrt{2}\,\mathrm{g}}

Show answer

Correct option: C

Q33JEE Main 2024 Jan 30 Shift 1Laws of MotionMedium

A spherical body of mass 100 g is dropped from a height of 10 m from the ground. After hitting the ground, the body rebounds to a height of 5 m. The impulse of force imparted by the ground to the body is given by : (given, g=9.8Ā m/s2\mathrm{g} = 9.8~\mathrm{m/s^2})

  1. A

    2.39Ā kgĀ msāˆ’12.39~\mathrm{kg~ms^{-1}}

  2. B

    43.2Ā kgĀ msāˆ’143.2~\mathrm{kg~ms^{-1}}

  3. C

    23.9Ā kgĀ msāˆ’123.9~\mathrm{kg~ms^{-1}}

  4. D

    4.32Ā kgĀ msāˆ’14.32~\mathrm{kg~ms^{-1}}

Show answer

Correct option: A

Q34JEE Main 2024 Jan 30 Shift 1Laws of MotionMedium

All surfaces shown in figure are assumed to be frictionless and the pulleys and the string are light. The acceleration of the block of mass 2 kg is :

Figure — described from the original paper

a 2 kg block on a 30°30° incline connected by a string over pulleys to a hanging 4 kg block; a movable pulley hangs from the ceiling

  1. A

    g3\frac{\mathrm{g}}{3}

  2. B

    g4\frac{\mathrm{g}}{4}

  3. C

    g2\frac{\mathrm{g}}{2}

  4. D

    g\mathrm{g}

Show answer

Correct option: A

Q35JEE Main 2024 Jan 30 Shift 1Work, Energy and PowerEasy

A particle is placed at the point A of a frictionless track ABC as shown in figure. It is gently pushed towards right. The speed of the particle when it reaches the point B is : (Take g=10Ā m/s2\mathrm{g} = 10~\mathrm{m/s^2}).

Figure — described from the original paper

a curved track with point A at height 1 m, point B at height 0.5 m inside a valley, and point C at the top on the right

  1. A

    10Ā m/s10~\mathrm{m/s}

  2. B

    10Ā m/s\sqrt{10}~\mathrm{m/s}

  3. C

    210Ā m/s2\sqrt{10}~\mathrm{m/s}

  4. D

    20Ā m/s20~\mathrm{m/s}

Show answer

Correct option: B

Q36JEE Main 2024 Jan 30 Shift 1GravitationMedium

The gravitational potential at a point above the surface of earth is āˆ’5.12Ɨ107Ā J/kg-5.12 \times 10^7~\mathrm{J/kg} and the acceleration due to gravity at that point is 6.4Ā m/s26.4~\mathrm{m/s^2}. Assume that the mean radius of earth to be 6400 km. The height of this point above the earth's surface is :

  1. A

    1600 km

  2. B

    1000 km

  3. C

    540 km

  4. D

    1200 km

Show answer

Correct option: A

Q37JEE Main 2024 Jan 30 Shift 1Properties of Solids and LiquidsEasy

Young's modules of material of a wire of length 'L' and cross-sectional area A is Y. If the length of the wire is doubled and cross-sectional area is halved then Young's modules will be :

  1. A

    4 Y4\,\mathrm{Y}

  2. B

    Y4\frac{\mathrm{Y}}{4}

  3. C

    Y\mathrm{Y}

  4. D

    2Y2\mathrm{Y}

Show answer

Correct option: C

Q38JEE Main 2024 Jan 30 Shift 1ThermodynamicsHard

Two thermodynamical processes are shown in the figure. The molar heat capacity for process A and B are CA\mathrm{C_A} and CB\mathrm{C_B}. The molar heat capacity at constant pressure and constant volume are represented by CP\mathrm{C_P} and CV\mathrm{C_V}, respectively. Choose the correct statement.

Figure — described from the original paper

log P vs log V graph; process A is a straight line through origin at angle tanā”āˆ’1γ\tan^{-1}\gamma, process B is a straight line at 45°45°

  1. A

    CA>CP>CV\mathrm{C_A} > \mathrm{C_P} > \mathrm{C_V}

  2. B

    CP>CV>CA=CB\mathrm{C_P} > \mathrm{C_V} > \mathrm{C_A} = \mathrm{C_B}

  3. C

    CA=0\mathrm{C_A} = 0 and CB=āˆž\mathrm{C_B} = \infty

  4. D

    CB=āˆž\mathrm{C_B} = \infty, CA=0\mathrm{C_A} = 0

Show answer

Correct option: C, D (dropped — all options accepted)

Q39JEE Main 2024 Jan 30 Shift 1Kinetic Theory of GasesEasy

At which temperature the r.m.s. velocity of a hydrogen molecule equal to that of an oxygen molecule at 47 °C47~°\mathrm{C} ?

  1. A

    20Ā K20~\mathrm{K}

  2. B

    80Ā K80~\mathrm{K}

  3. C

    āˆ’73Ā K-73~\mathrm{K}

  4. D

    4Ā K4~\mathrm{K}

Show answer

Correct option: A

Q40JEE Main 2024 Jan 30 Shift 1ElectrostaticsEasy

The electrostatic potential due to an electric dipole at a distance 'r' varies as :

  1. A

    1r\frac{1}{r}

  2. B

    1r2\frac{1}{r^2}

  3. C

    1r3\frac{1}{r^3}

  4. D

    rr

Show answer

Correct option: B

Q41JEE Main 2024 Jan 30 Shift 1Current ElectricityMedium

An electric toaster has resistance of 60Ā Ī©60~\Omega at room temperature (27 °C27~°\mathrm{C}). The toaster is connected to a 220 V supply. If the current flowing through it reaches 2.75 A, the temperature attained by toaster is around : ( if α=2Ɨ10āˆ’4/°C\alpha = 2 \times 10^{-4}/°\mathrm{C})

  1. A

    694 °C694~°\mathrm{C}

  2. B

    1667 °C1667~°\mathrm{C}

  3. C

    1694 °C1694~°\mathrm{C}

  4. D

    1235 °C1235~°\mathrm{C}

Show answer

Correct option: C

Q42JEE Main 2024 Jan 30 Shift 1Magnetic Effects of Current and MagnetismMedium

Two insulated circular loop A and B of radius 'a' carrying a current of 'I' in the anti clockwise direction as shown in the figure. The magnitude of the magnetic induction at the centre will be :

Figure — described from the original paper

two circular loops of equal radius with a common centre O, loop A horizontal and loop B vertical (mutually perpendicular planes), each carrying current I anticlockwise

  1. A

    μ0I2 a\frac{\mu_0 \mathrm{I}}{\sqrt{2}\,\mathrm{a}}

  2. B

    2 μ0Ia\frac{\sqrt{2}\,\mu_0 \mathrm{I}}{\mathrm{a}}

  3. C

    2 μ0Ia\frac{2\,\mu_0 \mathrm{I}}{\mathrm{a}}

  4. D

    μ0I2 a\frac{\mu_0 \mathrm{I}}{2\,\mathrm{a}}

Show answer

Correct option: A

Q43JEE Main 2024 Jan 30 Shift 1Electromagnetic Induction and Alternating CurrentsMedium

A series L.R circuit connected with an ac source E=(25sin⁔1000 t)Ā V\mathrm{E} = (25 \sin 1000\,\mathrm{t})~\mathrm{V} has a power factor of 12\frac{1}{\sqrt{2}}. If the source of emf is changed to E=(20sin⁔2000 t)Ā V\mathrm{E} = (20 \sin 2000\,\mathrm{t})~\mathrm{V}, the new power factor of the circuit will be :

  1. A

    12\frac{1}{\sqrt{2}}

  2. B

    13\frac{1}{\sqrt{3}}

  3. C

    15\frac{1}{\sqrt{5}}

  4. D

    17\frac{1}{\sqrt{7}}

Show answer

Correct option: C

Q44JEE Main 2024 Jan 30 Shift 1Electromagnetic WavesEasy

The electric field of an electromagnetic wave in free space is represented as Eāƒ—=E0cos⁔(ωtāˆ’kz) i^\vec{\mathrm{E}} = \mathrm{E}_0 \cos(\omega t - kz)\,\hat{i}. The corresponding magnetic induction vector will be :

  1. A

    Bāƒ—=E0Ccos⁔(ωtāˆ’kz) j^\vec{\mathrm{B}} = \dfrac{\mathrm{E}_0}{\mathrm{C}} \cos(\omega t - kz)\,\hat{j}

  2. B

    Bāƒ—=E0Ccos⁔(ωtāˆ’kz) j^\vec{\mathrm{B}} = \mathrm{E}_0 \mathrm{C} \cos(\omega t - kz)\,\hat{j}

  3. C

    Bāƒ—=E0Ccos⁔(ωt+kz) j^\vec{\mathrm{B}} = \dfrac{\mathrm{E}_0}{\mathrm{C}} \cos(\omega t + kz)\,\hat{j}

  4. D

    Bāƒ—=E0Ccos⁔(ωt+kz) j^\vec{\mathrm{B}} = \mathrm{E}_0 \mathrm{C} \cos(\omega t + kz)\,\hat{j}

Show answer

Correct option: A

Q45JEE Main 2024 Jan 30 Shift 1Wave OpticsMedium

The diffraction pattern of a light of wavelength 400 nm diffracting from a slit of width 0.2 mm is focused on the focal plane of a convex lens of focal length 100 cm. The width of the 1st1^{\text{st}} secondary maxima will be :

  1. A

    2 mm

  2. B

    0.2 mm

  3. C

    0.02 mm

  4. D

    2 cm

Show answer

Correct option: A

Q46JEE Main 2024 Jan 30 Shift 1Dual Nature of Matter and RadiationEasy

The work function of a substance is 3.0 eV. The longest wavelength of light that can cause the emission of photoelectrons from this substance is approximately;

  1. A

    400 nm

  2. B

    414 nm

  3. C

    200 nm

  4. D

    215 nm

Show answer

Correct option: B

Q47JEE Main 2024 Jan 30 Shift 1Atoms and NucleiEasy

The ratio of the magnitude of the kinetic energy to the potential energy of an electron in the 5th5^{\text{th}} excited state of a hydrogen atom is :

  1. A

    11

  2. B

    12\frac{1}{2}

  3. C

    14\frac{1}{4}

  4. D

    44

Show answer

Correct option: B

Q48JEE Main 2024 Jan 30 Shift 1Electronic DevicesMedium

A Zener diode of breakdown voltage 10 V is used as a voltage regulator as shown in the figure. The current through the Zener diode is :

Figure — described from the original paper

20 V battery in series with a 200 Ω200~\Omega resistor; a Zener diode in parallel with a branch containing a 500 Ω500~\Omega resistor

  1. A

    0

  2. B

    20 mA

  3. C

    30 mA

  4. D

    50 mA

Show answer

Correct option: C

Q49JEE Main 2024 Jan 30 Shift 1Current ElectricityMedium

A potential divider circuit is shown in figure. The output voltage V0\mathrm{V}_0 is :

Figure — described from the original paper

a 4 V battery across a series chain of a 3.3 kΩ3.3~\mathrm{k}\Omega resistor followed by seven 100 Ω100~\Omega resistors; V0\mathrm{V}_0 is taken across the last six 100 Ω100~\Omega resistors (tap after the first two resistors)

  1. A

    12 mV

  2. B

    2 mV

  3. C

    0.5 V

  4. D

    4 V

Show answer

Correct option: C

Q50JEE Main 2024 Jan 30 Shift 1Electromagnetic Induction and Alternating CurrentsMedium

Primary coil of a transformer is connected to 220 V ac. Primary and secondary turns of the transforms are 100 and 10 respectively. Secondary coil of transformer is connected to two series resistances shown in figure. The output voltage (V0)(\mathrm{V}_0) is :

Figure — described from the original paper

220 V ac source on transformer primary; secondary connected to a 15 kΩ15~\mathrm{k}\Omega resistor in series with a 7 kΩ7~\mathrm{k}\Omega resistor; V0\mathrm{V}_0 taken across the 7 kΩ7~\mathrm{k}\Omega resistor

  1. A

    22 V

  2. B

    7 V

  3. C

    15 V

  4. D

    44 V

Show answer

Correct option: B

Q51JEE Main 2024 Jan 30 Shift 1KinematicsMediumNumerical

The displacement and the increase in the velocity of a moving particle in the time interval of t to (t+1)(t+1) s are 125 m and 50 m/s, respectively. The distance travelled by the particle in (t+2)th(t+2)^{\text{th}} s is ________ m.

Show answer

Answer: 175

Q52JEE Main 2024 Jan 30 Shift 1Rotational MotionMediumNumerical

Consider a Disc of mass 5 kg, radius 2 m, rotating with angular velocity of 10 rad/s about an axis perpendicular to the plane of rotation. An identical disc is kept gently over the rotating disc along the same axis. The energy dissipated so that both the discs continue to rotate together without slipping is ________ J.

Figure — described from the original paper

a disc of mass 5 kg and radius 2 m rotating at ω=10Ā rad/s\omega = 10~\mathrm{rad/s} about a vertical axis through its centre

Show answer

Answer: 250

Q53JEE Main 2024 Jan 30 Shift 1Properties of Solids and LiquidsMediumNumerical

Each of three blocks P, Q and R shown in figure has a mass of 3 kg. Each of the wires A and B has cross-sectional area 0.005Ā cm20.005~\mathrm{cm^2} and Young's modulus 2Ɨ1011Ā NĀ māˆ’22 \times 10^{11}~\mathrm{N~m^{-2}}. Neglecting friction, the longitudinal strain on wire B is ________ Ɨ10āˆ’4\times 10^{-4}. (Take g=10Ā m/s2\mathrm{g} = 10~\mathrm{m/s^2})

Figure — described from the original paper

blocks P and Q on a horizontal table connected by wire A; wire B runs from Q over a pulley at the table edge down to hanging block R

Show answer

Answer: 2

Q54JEE Main 2024 Jan 30 Shift 1WavesMediumNumerical

In a closed organ pipe, the frequency of fundamental note is 30 Hz. A certain amount of water is now poured in the organ pipe so that the fundamental frequency is increased to 110 Hz. If the organ pipe has a cross-sectional area of 2Ā cm22~\mathrm{cm^2}, the amount of water poured in the organ tube is ________ g. (Take speed of sound in air is 330 m/s)

Show answer

Answer: 400

Q55JEE Main 2024 Jan 30 Shift 1ElectrostaticsMediumNumerical

A capacitor of capacitance C and potential V has energy E. It is connected to another capacitor of capacitance 2 C and potential 2 V. Then the loss of energy is x3 E\frac{x}{3}\,\mathrm{E}, where xx is ________.

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Answer: 2

Q56JEE Main 2024 Jan 30 Shift 1Current ElectricityMediumNumerical

Two cells are connected in opposition as shown. Cell E1\mathrm{E}_1 is of 8 V emf and 2 Ω2~\Omega internal resistance; the cell E2\mathrm{E}_2 is of 2 V emf and 4 Ω4~\Omega internal resistance. The terminal potential difference of cell E2\mathrm{E}_2 is ________ V.

Figure — described from the original paper

a closed loop with cells E1\mathrm{E}_1 and E2\mathrm{E}_2 connected in opposition between points A, B and C

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Answer: 6

Q57JEE Main 2024 Jan 30 Shift 1Magnetic Effects of Current and MagnetismMediumNumerical

The horizontal component of earth's magnetic field at a place is 3.5Ɨ10āˆ’5Ā T3.5 \times 10^{-5}~\mathrm{T}. A very long straight conductor carrying current of 2Ā A\sqrt{2}~\mathrm{A} in the direction from South east to North West is placed. The force per unit length experienced by the conductor is ________ Ɨ10āˆ’6Ā N/m\times 10^{-6}~\mathrm{N/m}.

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Answer: 35

Q58JEE Main 2024 Jan 30 Shift 1Electromagnetic Induction and Alternating CurrentsMediumNumerical

A ceiling fan having 3 blades of length 80 cm each is rotating with an angular velocity of 1200 rpm. The magnetic field of earth in that region is 0.5 G and angle of dip is 30°30°. The emf induced across the blades is Nπ×10āˆ’5Ā V\mathrm{N}\pi \times 10^{-5}~\mathrm{V}. The value of N is ________.

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Answer: 32

Q59JEE Main 2024 Jan 30 Shift 1Ray OpticsMediumNumerical

The distance between object and its two times magnified real image as produced by a convex lens is 45 cm. The focal length of the lens used is ________ cm.

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Answer: 10

Q60JEE Main 2024 Jan 30 Shift 1Atoms and NucleiEasyNumerical

A electron of hydrogen atom on an excited state is having energy En=āˆ’0.85Ā eV\mathrm{E_n} = -0.85~\mathrm{eV}. The maximum number of allowed transitions to lower energy level is ________.

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Answer: 6