JEE MAIN - Physics (2024 - 30th January Morning Shift)
- 4A particle of mass $$\mathrm{m}$$ is projected with a velocity '$$\mathrm{u}$$' making an angle of $$30^{\circ}$$ with the horizontal. The magnitude of angular momentum of the projectile about the point of projection when the particle is at its maximum height $$\mathrm{h}$$ is :Odpověď(D)$$\frac{\sqrt{3}}{16} \frac{\mathrm{mu}^3}{\mathrm{~g}}$$
- 9
Two thermodynamical processes are shown in the figure. The molar heat capacity for process A and B are $$\mathrm{C}_{\mathrm{A}}$$ and $$\mathrm{C}_{\mathrm{B}}$$. The molar heat capacity at constant pressure and constant volume are represented by $$\mathrm{C_P}$$ and $$\mathrm{C_V}$$, respectively. Choose the correct statement.
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Odpověď(A)$$\mathrm{C_P>C_B>C_A>C_V}$$ - 10The electric field of an electromagnetic wave in free space is represented as $$\overrightarrow{\mathrm{E}}=\mathrm{E}_0 \cos (\omega \mathrm{t}-\mathrm{kz}) \hat{i}$$. The corresponding magnetic induction vector will be :Odpověď(B)$$\overrightarrow{\mathrm{B}}=\frac{\mathrm{E}_0}{\mathrm{C}} \cos (\omega \mathrm{t}-\mathrm{kz}) \hat{j}$$
- 12
Match List I with List II.
List I List II (A) Coefficient of viscosity (I) $$\left[\mathrm{M} \mathrm{L}^2 \mathrm{~T}^{-2}\right]$$ (B) Surface tension (II) $$\left[\mathrm{M} \mathrm{L}^2 \mathrm{~T}^{-1}\right]$$ (C) Angular momentum (III) $$\left[\mathrm{M} \mathrm{L}^{-1} \mathrm{~T}^{-1}\right]$$ (D) Rotational kinetic energy (IV) $$\left[\mathrm{M} \mathrm{L}^0 \mathrm{~T}^{-2}\right]$$ Choose the correct answer from the options given below :
Odpověď(D)(A)-(III), (B)-(IV), (C)-(II), (D)-(I) - 17An electric toaster has resistance of $$60 \Omega$$ at room temperature $$\left(27^{\circ} \mathrm{C}\right)$$. The toaster is connected to a $$220 \mathrm{~V}$$ supply. If the current flowing through it reaches $$2.75 \mathrm{~A}$$, the temperature attained by toaster is around : ( if $$\alpha=2 \times 10^{-4}$$/$$^\circ \mathrm{C}$$)Odpověď(D)1694 $$^\circ$$C
- 18A spherical body of mass $$100 \mathrm{~g}$$ is dropped from a height of $$10 \mathrm{~m}$$ from the ground. After hitting the ground, the body rebounds to a height of $$5 \mathrm{~m}$$. The impulse of force imparted by the ground to the body is given by : (given, $$\mathrm{g}=9.8 \mathrm{~m} / \mathrm{s}^2$$)Odpověď(B)$$2.39 \mathrm{~kg} \mathrm{~ms}^{-1}$$
- 20The gravitational potential at a point above the surface of earth is $$-5.12 \times 10^7 \mathrm{~J} / \mathrm{kg}$$ and the acceleration due to gravity at that point is $$6.4 \mathrm{~m} / \mathrm{s}^2$$. Assume that the mean radius of earth to be $$6400 \mathrm{~km}$$. The height of this point above the earth's surface is :Odpověď(A)1600 km
- 21The horizontal component of earth's magnetic field at a place is $$3.5 \times 10^{-5} \mathrm{~T}$$. A very long straight conductor carrying current of $$\sqrt{2} \mathrm{~A}$$ in the direction from South east to North West is placed. The force per unit length experienced by the conductor is __________ $$\times 10^{-6} \mathrm{~N} / \mathrm{m}$$.Odpověď35
- 22
Two cells are connected in opposition as shown. Cell $$\mathrm{E}_1$$ is of $$8 \mathrm{~V}$$ emf and $$2 \Omega$$ internal resistance; the cell $$\mathrm{E}_2$$ is of $$2 \mathrm{~V}$$ emf and $$4 \Omega$$ internal resistance. The terminal potential difference of cell $$\mathrm{E}_2$$ is __________ V.
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Odpověď6 - 26In a closed organ pipe, the frequency of fundamental note is $$30 \mathrm{~Hz}$$. A certain amount of water is now poured in the organ pipe so that the fundamental frequency is increased to $$110 \mathrm{~Hz}$$. If the organ pipe has a cross-sectional area of $$2 \mathrm{~cm}^2$$, the amount of water poured in the organ tube is __________ g. (Take speed of sound in air is $$330 \mathrm{~m} / \mathrm{s}$$)Odpověď400
- 27
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Consider a Disc of mass $$5 \mathrm{~kg}$$, radius $$2 \mathrm{~m}$$, rotating with angular velocity of $$10 \mathrm{~rad} / \mathrm{s}$$ 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.
Odpověď250 - 28The displacement and the increase in the velocity of a moving particle in the time interval of $$t$$ to $$(t+1) \mathrm{s}$$ are $$125 \mathrm{~m}$$ and $$50 \mathrm{~m} / \mathrm{s}$$, respectively. The distance travelled by the particle in $$(\mathrm{t}+2)^{\mathrm{th}} \mathrm{s}$$ is _________ m.Odpověď175
- 29
Each of three blocks $$\mathrm{P}, \mathrm{Q}$$ and $$\mathrm{R}$$ shown in figure has a mass of $$3 \mathrm{~kg}$$. Each of the wires $$\mathrm{A}$$ and $$\mathrm{B}$$ has cross-sectional area $$0.005 \mathrm{~cm}^2$$ and Young's modulus $$2 \times 10^{11} \mathrm{~N} \mathrm{~m}^{-2}$$. Neglecting friction, the longitudinal strain on wire $$B$$ is ________ $$\times 10^{-4}$$. (Take $$\mathrm{g}=10 \mathrm{~m} / \mathrm{s}^2$$)
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Odpověď2 - 30A ceiling fan having 3 blades of length $$80 \mathrm{~cm}$$ each is rotating with an angular velocity of 1200 $$\mathrm{rpm}$$. The magnetic field of earth in that region is $$0.5 \mathrm{G}$$ and angle of dip is $$30^{\circ}$$. The emf induced across the blades is $$\mathrm{N} \pi \times 10^{-5} \mathrm{~V}$$. The value of $$\mathrm{N}$$ is _________.Odpověď32
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