Q31JEE Main 2024 Jan 30 Shift 1Units and MeasurementsEasy
Match List - I with List - II.
List - I
List - II
(A)
Coefficient of viscosity
(I)
[ML2Tā2]
(B)
Surface tension
(II)
[ML2Tā1]
(C)
Angular momentum
(III)
[MLā1Tā1]
(D)
Rotational kinetic energy
(IV)
[ML0Tā2]
Choose the correct answer from the options given below :
A
(A)-(I), (B)-(II), (C)-(III), (D)-(IV)
B
(A)-(III), (B)-(IV), (C)-(II), (D)-(I)
C
(A)-(II), (B)-(I), (C)-(IV), (D)-(III)
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° 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 :
A
23āāgmu2ā
B
zero
C
163āāgmu3ā
D
2āgmu3ā
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)
A
2.39Ā kgĀ msā1
B
43.2Ā kgĀ msā1
C
23.9Ā kgĀ msā1
D
4.32Ā kgĀ msā1
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 ā described from the original paper
a 2 kg block on a 30° incline connected by a string over pulleys to a hanging 4 kg block; a movable pulley hangs from the ceiling
A
3gā
B
4gā
C
2gā
D
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).
Figure ā 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
A
10Ā m/s
B
10āĀ m/s
C
210āĀ m/s
D
20Ā 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 ā5.12Ć107Ā J/kg and the acceleration due to gravity at that point is 6.4Ā m/s2. Assume that the mean radius of earth to be 6400 km. The height of this point above the earth's surface is :
A
1600 km
B
1000 km
C
540 km
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 :
A
4Y
B
4Yā
C
Y
D
2Y
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 CAā and CBā. The molar heat capacity at constant pressure and constant volume are represented by CPā and CVā, respectively. Choose the correct statement.
Figure ā described from the original paper
log P vs log V graph; process A is a straight line through origin at angle tanā1γ, process B is a straight line at 45°
A
CAā>CPā>CVā
B
CPā>CVā>CAā=CBā
C
CAā=0 and CBā=ā
D
CBā=ā, CAā=0
Show answer
Correct option: C, D (dropped ā 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 °C ?
A
20Ā K
B
80Ā K
C
ā73Ā K
D
4Ā 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 :
A
r1ā
B
r21ā
C
r31ā
D
r
Show answer
Correct option: B
Q41JEE Main 2024 Jan 30 Shift 1Current ElectricityMedium
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 ā 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
A
2āaμ0āIā
B
a2āμ0āIā
C
a2μ0āIā
D
2aμ0āIā
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=(25sin1000t)Ā V has a power factor of 2ā1ā. If the source of emf is changed to E=(20sin2000t)Ā V, the new power factor of the circuit will be :
A
2ā1ā
B
3ā1ā
C
5ā1ā
D
7ā1ā
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 E=E0ācos(Ļtākz)i^. The corresponding magnetic induction vector will be :
A
B=CE0āācos(Ļtākz)j^ā
B
B=E0āCcos(Ļtākz)j^ā
C
B=CE0āācos(Ļt+kz)j^ā
D
B=E0āCcos(Ļt+kz)j^ā
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 1st secondary maxima will be :
A
2 mm
B
0.2 mm
C
0.02 mm
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;
A
400 nm
B
414 nm
C
200 nm
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 5th excited state of a hydrogen atom is :
A
1
B
21ā
C
41ā
D
4
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 :
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 (V0ā) is :
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) s are 125 m and 50 m/s, respectively. The distance travelled by the particle in (t+2)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 ā described from the original paper
a disc of mass 5 kg and radius 2 m rotating at Ļ=10Ā 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 cm2 and Young's modulus 2Ć1011Ā NĀ mā2. Neglecting friction, the longitudinal strain on wire B is ________ Ć10ā4. (Take g=10Ā m/s2)
Figure ā 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 cm2, 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 3xāE, where x is ________.
Show answer
Answer: 2
Q56JEE Main 2024 Jan 30 Shift 1Current ElectricityMediumNumerical
a closed loop with cells E1ā and E2ā connected in opposition between points A, B and C
Show answer
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 3.5Ć10ā5Ā T. A very long straight conductor carrying current of 2āĀ A in the direction from South east to North West is placed. The force per unit length experienced by the conductor is ________ Ć10ā6Ā N/m.
Show answer
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°. The emf induced across the blades is NĻĆ10ā5Ā V. The value of N is ________.
Show answer
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.
Show answer
Answer: 10
Q60JEE Main 2024 Jan 30 Shift 1Atoms and NucleiEasyNumerical
A electron of hydrogen atom on an excited state is having energy Enā=ā0.85Ā eV. The maximum number of allowed transitions to lower energy level is ________.