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InterviewSolution
This section includes InterviewSolutions, each offering curated multiple-choice questions to sharpen your knowledge and support exam preparation. Choose a topic below to get started.
| 2751. |
If density of earth increased 4 times and its radius become half of what it is, our weight will ?A. be four times its present valueB. be doubledC. remain sameD. be halved |
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Answer» Correct Answer - B `g prop rho R`. If density of earth is increased four times and its radius become half, then the value of acceleration due to gravity becomes due to which our weight get double. |
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| 2752. |
If density of earth increased 4 times and its radius become half of what it is, our weight willA. Be four times its present valueB. Be doubledC. Remain sameD. Be halved |
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Answer» Correct Answer - B |
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| 2753. |
STATEMENT -1 : The orbital speed of geostationary satellite is nearly 3.1 km/s. STATEMENT -2 : The rotation of geostationary satellite around earth is from west to east. STATEMENT -3 : The total mechanical energy of an orbiting satellite is smaller than its kinetic energy.A. T F TB. F F FC. T T TD. T F F |
| Answer» Correct Answer - C | |
| 2754. |
Can you think of two particles which do not exert gravitational force on each other? |
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Answer» Two particles which do not exert gravitational force on each other will be mass less particles. But every particle has even a little mass. Hence we cannot find two particles which do not exert gravitational force on each other. |
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| 2755. |
Can you think of two particles which do not exert a gravitational force on each other? |
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Answer» No. Since the particles have mass, they will exert a gravitational force on each other. |
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| 2756. |
STATEMENT -1 : A small object if released from rest from a point upon the axis of a large mass circular ring, but very near to the centre of ring, will perform SHM. and STATEMENT -2 : The gravitational field of mass circular ring changes non-linearly with the axial distance, near the centre.A. Statement 1- True, Statement -2 is True, Statement -2 is a correct explanation for Statement -14B. Statement -1 is True, Statement -2 is True, Statement -2 is NOT a correct explanation for Statement -14C. Statement -1 is True, Statement -2 is FalseD. Statement -1 is False, Statement -2 is True |
| Answer» Correct Answer - C | |
| 2757. |
STATEMENT -1 : The weight of a person on earth is different at daytime and at night time. and STATEMENT -2 : Distance of the person is different from Sun in day time and in night time.A. Statement 1- True, Statement -2 is True, Statement -2 is a correct explanation for Statement -6B. Statement -1 is True, Statement -2 is True, Statement -2 is NOT a correct explanation for Statement -6C. Statement -1 is True, Statement -2 is FalseD. Statement -1 is False, Statement -2 is True |
| Answer» Correct Answer - D | |
| 2758. |
STATEMENT -1 : The centre of gravity of a spherically symmetric body of uniform mass density, will lie upon the geometrical centre. and STATEMENT -2 : The location of centre of gravity depends upon the distribution of mass as well as variation of g.A. Statement 1- True, Statement -2 is True, Statement -2 is a correct explanation for Statement -13B. Statement -1 is True, Statement -2 is True, Statement -2 is NOT a correct explanation for Statement -13C. Statement -1 is True, Statement -2 is FalseD. Statement -1 is False, Statement -2 is True |
| Answer» Correct Answer - D | |
| 2759. |
Assertion: The gravitational force on a particle inside a spherical shell is zero. Reason: The shell shields other bodies outside it form exerting gravitational forces on a particle inside.A. If both the assertion and reason are true and reason is a true explantion of the assertion.B. If both the assertion and reason are true but the reason is not true the correct explantion of the assertion.C. If the assertion is true but reason falseD. If both the assertion and reason are false. |
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Answer» Correct Answer - B The gravitational force on a particle inside a spherical shell is zero. However, unlike a metallic shell which sheilds electrical forces. The shell does not shield other bodies outside it form exerting gravitational forces on a particle inside. |
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| 2760. |
STATEMENT -1 : Gravitational field inside a spherical mass shell is zero even if the mass distribution is uniform or non-uniform. and STATEMENT -2 : A mass object when placed inside a mass spherical shell, is protected from the gravitational field of another mass object placed outside the shell.A. Statement 1- True, Statement -2 is True, Statement -2 is a correct explanation for Statement -10B. Statement -1 is True, Statement -2 is True, Statement -2 is NOT a correct explanation for Statement -10C. Statement -1 is True, Statement -2 is FalseD. Statement -1 is False, Statement -2 is True |
| Answer» Correct Answer - C | |
| 2761. |
Inside a uniform spherical shell (a) the gravitational potential is zero (b) the gravitational field is zero (c) the gravitational potential is same everywhere (d) the gravitational field is same everywhere. |
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Answer» (b) the gravitational field is zero EXPLANATION: Inside a uniform spherical shell the gravitational potential is -GM/a every where. Where a = radius of the shell. So (a) is not true but (c) is true. The field is zero and same everywhere inside a shell, so (b) and (d) is true. |
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| 2762. |
A uniform spherical shell gradually shrinks maintaining its shape. The gravitational potential at the centre (a) increases (b) decreases (c) remains constant (d) oscillates. |
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Answer» (b) Decreases EXPLANATION: Gravitational potential at the centre of spherical shell =−GM/R |
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| 2763. |
Two satellites A and B move round the earth in the same orbit. The mass of B is twice the mass of A. (a) Speeds of A and B are equal. (b) The potential energy of earth + A is same as that of earth + B. (c) The kinetic energy of A and B are equal. (d) The total energy of earth + A is same as that of earth + B. |
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Answer» (a) Speeds of A and B are equal. EXPLANATION: The velocity of a satellite in an orbit, v = √(GM/a). So the velocity of a satellite in an orbit is in independent of its mass. So (a) is true. The potential energy of the earth satellite system = -GMm/a, so it is dependent on the mass of the satellite. Hence (b) is not true. Since the K.E. (½mv²) depends on the mass, so (c) is not true. Again the total energy of the system = -GMm/2a. It is also dependent on mass, so (d) is not true. |
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| 2764. |
Two satellites A and B move round the earth in the same orbit. The mass of B is twice the mass of A.(a) Speeds of A and B are equal.(b) The potential energy of earth + A is same as that of earth + B.(c) The kinetic energy of A and B are equal.(d) The total energy of earth + A is same as that of earth + B. |
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Answer» (a) Speeds of A and B are equal. EXPLANATION: The velocity of a satellite in an orbit, v = √(GM/a). So the velocity of a satellite in an orbit is in independent of its mass. So (a) is true. The potential energy of the earth satellite system = -GMm/a, so it is dependent on the mass of the satellite. Hence (b) is not true. Since the K.E. (½mv²) depends on the mass, so (c) is not true. Again the total energy of the system = -GMm/2a. It is also dependent on mass, so (d) is not true. |
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| 2765. |
Two bodies of mass `10^(2)` kg and `10^(3)` kg are lying 1 m apart . The gravitational potential at the mid-point of the line joining them is |
| Answer» Correct Answer - `-2200xx6.67xx10^(-11) J//kg` | |
| 2766. |
Two spherical balls of mass 10 kg each are placed 100 m apart. Find the fraviational force of attraction between them. |
| Answer» `F=(Gm_(1)m_(2))/r^(2) =(6.67xx10^(11)xx10xx10)/((100)^(2))=6.67xx10^(13)N`. | |
| 2767. |
Two particles of masses 1.0 kg and 2.0 kg are placed at a separation of 50 cm. Assuming that the only forces acting on the particles are their mutual gravitation find the initial acceleration of the two particles. |
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Answer» Correct Answer - A::B::C `a_(1) = (F)/(m_(1)) = (Gm_(1)m_(2))/(r^(2)) = (Gm_(2))/(r^(2))` `=((6.67 xx 10^(-11))(2))/((0.5)^(2))` `= 5.3 xx 10^(-10) m//s^(2)` Similarly, `a_(2) = (Gm_(1))/(r^(2))` |
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| 2768. |
Two particles of masses 1.0 kg and 2.0 kg are placed at a separation of 50 cm. Assuming that the only foces acting on the particles are their mutual gravitation find the initial acceleration of hthe two particles. |
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Answer» The force of gravitastion exerted by one particle on another is `F_1=(Gm_1m_2)/r^2` `=96.67xx10^-11(N-m^2)/(kg^2)(1.0kg)xx(2.0kg))/((0.5m)^2)` `=5.3xx10^-10N` The acceleration of 1.0 kg particle is `a_`=F/m_1=(5.3xx10^-10N)/(1.0kg)` `=5.3xx10^-10N ms^2-` This acceleration is towards the 2.0 kg particle. The acceleration of the 2.0 kg particle is `a_2=F/m_2=(5.3xx10^-10N)/(2.0kg)` `=2.65xx10^-10ms^-2` This acceleration is towards the 1.0 kg particle. |
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| 2769. |
For the double star system, the two stars having masses `m_(1)` and `m_(2) `are separated b a distance `r`. They are revolgin about their common centre of mass in radii `r_(1)` and `r_(2)` respectively. Which of the following is/are incorrect.?A. The whole system can be studied can be studied by replacing it by a single mass `(m_(1)m_(2))/(m_(1)+m_(2))` revolgin about the center of mass.B. The angular velocity of `m_(2)` is less than that of `m_(1)`C. Force acting on `m_(1)` is `(Gm_(1)m_(2))/(r_(1)^(2))` and that acting on `m_(2)` is `(Gm_(1)m_(2))/(r_(2)^(2))`D. For acting on `m_(2)` is `(Gm_(1)m_(2))/(r^(2))m_(2)` |
| Answer» Correct Answer - A::B::C | |
| 2770. |
A body is projected vertically upwards from the surface of the earth with a velocity equal to half of escape velocity of the earth. If `R` is radius of the earth, maximum height attained by the body from the surface of the earth isA. `R//6`B. `R//3`C. `2R//3`D. `R` |
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Answer» Correct Answer - B Maximum height attained by body `h=R[(v^(2))/(v_(e)^(2)-v^(2))]rArr h=R[(v_(e)^(2)//4)/(v_(e)^(2)-v_(e)^(2)//4)]=R[(v_(e)^(2)//4)/(3_(e)^(2)//4)]rArrh=(R)/(3)`. |
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| 2771. |
A body is projected vertically upwards from the surface of the earth with a velocity equal to half of escape velocity of the earth. If `R` is radius of the earth, maximum height attained by the body from the surface of the earth isA. `(R)/(6)`B. `(R)/(3)`C. `(2R)/(3)`D. `R` |
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Answer» Correct Answer - B Applying conservation of mechanical energy, `(1)/(2)m((v_(e))/(2))^(2)=(mgh)/(1+(h)/(R))or(v_(e)^(2))/(8)=(gh)/(1+(h)/(R))` or `(2gR)/(8)=(gh)/(1+h//R)`....(i) `(because v_(e) = sqrt(2gR))` On solving Eq. (i), we get `h= (R)/(3)`. |
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| 2772. |
A bullet is fired up with velocity equal to escape velocity. The sum of its potential energy and kinetic energy isA. zeroB. positiveC. negativeD. infinity |
| Answer» Correct Answer - a | |
| 2773. |
A bullet is fired up with velocity less than escape velocity. The sum of its potential energy and kinetic energy isA. zeroB. positiveC. negativeD. infinity |
| Answer» Correct Answer - c | |
| 2774. |
Escape velocity from the moon surface is less than that on the earth surface, becauseA. moon has no atmosphere while the earth hasB. radius of moon is less than that of the earthC. moon is nearer to the sunD. moon is attracted by other planets |
| Answer» Correct Answer - b | |
| 2775. |
A body is projected vertically upwards from the surface of a planet of radius `R` with a velocity equal to half the escape velocity for that planet. The maximum height attained by the body isA. R /3B. R /2C. R /4D. R /5 |
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Answer» Correct Answer - A |
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| 2776. |
The escape velocity for a planet is `v_e`. A particle is projected from its surface with a speed `v`. For this particle to move as a satellite around the planet.A. `(v_(e))/2 lt v lt v_(e)`B. `(v_(e))/(sqrt(2)) lt v lt v_(e)`C. `v_(e) lt v lt sqrt(2)v_(e)`D. `(v_(e))/(sqrt(2)) lt v lt (v_(e))/2` |
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Answer» Correct Answer - B For a satallite close to earth `V_(O)=sqrt(gR)=v_(min)` Escape velocity `v_(e)=sqrt(2gR)=v_(min)` `V_(O)=(v_(e))/(sqrt(2))` `(v_(e))/(sqrt(2)) lt v lt v_(e)` |
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| 2777. |
The escape velocity of an object projected from the surface of a given planet is independent ofA. mass of the bodyB. mass of the planetC. average radius of the planetD. average radius of the planet |
| Answer» Correct Answer - a | |
| 2778. |
A particle is projected from the surface of earth with velocity equal to its escape velocity , at `45^(@)` with horizontal . What is the angle of its velocity with horizontal at height h = R . (Here horizontal at some point means a line parallel to tangent on earth just below that point . )A. `30^(@)`B. `60^(@)`C. `cos^(-1) ((1)/(3))`D. `cos^(-1) ((1)/(4))` |
| Answer» Correct Answer - B | |
| 2779. |
Statement-1: If an object is projected from earth surface with escape velocity path of object will be parabola. Statement-2: When object is projected with velocity less than escape velocity from horizontal surface and greter than orbital velocity. path of object will be ellipse.A. Statement-1 is true, statement-2 is true, Statement-2 is a correct explanation for statement-1.B. Statement-1 is true, Statement-2 is true, statement-2 is Not a correct explanation for statement-1C. Statement-1 is true, Statement-2 is false.D. Statement-1 is false Statement-2 is True. |
| Answer» Correct Answer - b | |
| 2780. |
Which of the following quantities remain constant in a planetary motion (consider elliptical orbits)as seen from the sun?A. linear momentumB. kinetic energyC. potential energyD. angular momentum |
| Answer» Correct Answer - d | |
| 2781. |
Which of the following quantities remain constant in a planetary motion (consider elliptical orbits)as seen from the sun?A. speedB. Angular speedC. kinetic energyD. Angular momentum |
| Answer» Correct Answer - D | |
| 2782. |
When a satellite is moving around the earth with velocity `v`, then to make the satellite escape, the minimum percentage increase in its velocity should beA. `41.4%`B. `82.8%`C. `58.6%`D. `100%` |
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Answer» Correct Answer - a `V_(e)=sqrt2V_(c)` `(V_(e))/(V_(c))=1.414` `(V_(e)-V_(c))/(V_(c))=1.414-1=0.414=41.4%`. |
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| 2783. |
If the mass of sun were len times smaller and gravitational consitant `G` were ten times larger in magnitudesA. Walking on ground would became more difficult.B. the acceleration due to gravity on earth will not change.C. raindrops will fall much faster.D. airplanes will have to travel much faster. |
| Answer» Correct Answer - A::C::D | |
| 2784. |
If the mass of sun were ten times smaller and gravitational constant G were ten times larger in magnitudes- (a) walking on ground would became more difficult. (b) the acceleration due to gravity on earth will not change. (c) raindrops will fall much faster. (d) airplanes will have to travel much faster. |
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Answer» (a) walking on ground would became more difficult. (c) raindrops will fall much faster. (d) airplanes will have to travel much faster. |
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| 2785. |
If the earth suddenly stops rotating about its axis, what would be the effect on the value of ‘g’? Will this effect be same at all places? |
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Answer» The value of ′g′ at a place on earth of latitude λ is g′ = g −\(R\omega^2\cos^2\lambda\). For any value of ω, g′ < g. It means the value of ′g′ decreases due to rotation of the earth. If earth stops rotating, the value of g would increase. The effect will be maximum at equator and least at pole. |
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| 2786. |
Calculate the value of acceleration due to gravity at a place of latitude `45^(@)` . Radius of the earth = `6.38 xx 10^(3)` km . |
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Answer» Correct Answer - `9.783 ms^(-2)` |
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| 2787. |
Statement I: If the earth suddenly stops rotating about its axis, then the acceleration due to gravity will become the same at all the places. Statement II: The value of acceleration due to gravity is independent of rotation of the earth.A. If both assertion and reason are true and the reason is the correct explanation of the assertion.B. If both assertion and reason are true but reason is not the correct explanation of the assertion.C. If assertion is true but reason is false.D. If the assertion and reason both are false. |
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Answer» Correct Answer - C |
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| 2788. |
The change in the value of `g` at a height `h` above the surface of the earth is the same as at a depth d below the surface of earth. When both `d` and `h` are much smaller than the radius of earth, then which one of the following is correct?A. d = hB. d = 2hC. d = h/2D. `d=h^(2)` |
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Answer» Correct Answer - b `g_(h)=g_(d)` `therefore" "1-(2h)/(R)=1-(d)/(R)" "therefore d=2h` |
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