Gravitation - Quiz 6

GRAVITATION QUIZ-6

Dear Readers,

JEE Advanced Physics Syllabus can be referred by the IIT aspirants to get a detailed list of all topics that are important in cracking the entrance examination. JEE Advanced syllabus for Physics has been designed in such a way that it offers very practical and application-based learning to further make it easier for students to understand every concept or topic by correlating it with day-to-day experiences. In comparison to the other two subjects, the syllabus of JEE Advanced for physics is developed in such a way so as to test the deep understanding and application of concepts.

Gravitation is an easy to understand and a highly scoring topic. It might have a 1% weightage in the entire JEE Physics portion but do not neglect. You can practice these questions on regular basis to know what are the important points to remember at the moment when gravitation question comes.

Q1.If a man at the equator would weigh (3/5)th of his weight, the angular speed of the earth is

•  √(2g/5R)
•  √(g/R)
•   √(R/g)
•  √(2R/5g)

Solution

 

Q2.A projectile is fired vertically upwards from the surface of the earth with a velocity Kv_e, where v_e is the escape velocity and k <1. If R is the radius of the earth, the maximum height to which it will rise, measured from the centre of the earth, will be (neglect air resistance)

•  (1-k²)/R
•  R/(1-k²)
•  R(1-k)²
•  R/(1+k²)

Solution

Q3.A satellite is orbiting around the earth in a circular orbit of radius r. A particle of mass m is projected from the satellite in a forward direction with a velocity v=2/3 times the orbital velocity (this velocity is given w.r.t. earth). During subsequent motion of the particle, its minimum distance from the centre of earth is

•  r/2
•  r
•  2r/3
•  4r/5

Solution

Q4.The escape velocity for a body projected vertically upwards from the surface of the earth is 11.2 km s^-1. If the body is projected in a direction making an angle 45° with the vertical, the escape velocity will be

•  11.2/√2 km s^-1
•  11.2×√2 km s^-1
•  11.2×2 km s^-1
•  11.2 km s^-1

Solution

Q5.If the distance between the earth and the Sun were half its present value, the number of days in a year would have been

•  64.5
•  129
•  182.5
•  730

Solution

Q6.If an artificial satellite is moving in a circular orbit around the earth with a speed equal to half the magnitude of the escape velocity from the earth, the height of the satellite above the surface of the earth is

•  2R
•  R/2
•  R
•  R/4

Solution

Q7.A thin uniform annular disc (see figure) of mass M has outer radius 4R and inner radius 3R. The work required to take a unit mass from point P on its axis to infinity is

•  2GM(4√2-5)/7R
•  -2GM(4√2-5)/7R
•  GM/4R
•  2GM(√2-1)/5R

Solution

Q8.The gravitational potential energy of an isolated system of three particles, each of mass m, at the three corners of an equilateral triangle of side l is

•  -(Gm²)/l
•  -(Gm²)/2l
•  -(2Gm²)/l
•  -(3Gm²)/l

Solution

Q9.If the radius of the earth decreases by 10%, the mass remaining unchanged, what will happen to the acceleration due to gravity?

•  Decreases by 19%
•  Increases by 19%
•  Decreases by more than 19%
•  Increases by more than 19%

Solution

Q10.A body is thrown from the surface of the earth with velocity (gR_e)/2, where R_e is the radius of the earth at some angle from the vertical. If the maximum height reached by the body is R_e4, then the angle of projection with the vertical is

•  sin^-1⁡(√5/4)
•  cos^-1⁡(√5/4)
•  sin^-1⁡(√3/2)
• None of these

Solution