# First Year Physics Circular Motion 67. The artificial gravity is created in the satellite toa) Increase the orbital speed of the satelliteb) Keep the satellite in its orbitc) Overcome the weightlessness experienced by the astronautd) K

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##### 67. The artificial gravity is created in the satellite toa) Increase the orbital speed of the satelliteb) Keep the satellite in its orbitc) Overcome the weightlessness experienced by the astronautd) Keep the orbital radius of the satellite constant

62. The weight of a man in an elevator moving down with an acceleration of 9.8 \mathrm{~m} / \mathrm{s}^{2} will becomea) Doubleb) Halfc) Zerod) Unchanged

A body of moment of inertia I=0.80 \mathrm{~kg} \mathrm{} \mathrm{m}^{2} about a fixed axis rotates with a constant angular velocity of 100 rad s^{-1} . Calculate its angular momentum L and the torque to sustain this motion.

9. When a body moves in a circle the angle between its linear velocity and angular velocity is always.a) 180^{\circ} b) 0^{\circ} c) 90^{\circ} d) 45^{\circ}

Explain how many minimum number of geo-stationary satellites are required for global coverage of T . V transmission?

45. The value of gravitational constant was determined bya) Newtonb) Keplerc) Cavendishd) Maxwell

A student holds two dumb-bells without stretched arms while sitting on a turn table. He is given a push until he is rotating at certain angular velocity. The student then pulls the dumbbell towards his chest (Fig. 5.25). What will be the effect on rate of rotation?

41. Which one of the following can be used to determine the mass of earth?a) Keplers lawb) Newtons law of motionc) Coulombs lawd) Newtons law of gravitation

A disc and a hoop start moving down from the top of an inclined plane at the same time. Which one will be moving faster on reaching the bottom?

4. Geo-stationary satellite completes one rotation around earth in.a) 3 hoursb) 6 hoursc) 9 hoursd) 24 hours

71. The expression of moment of Inertia "I" is:a) mab) m c) \mathrm{mr}^{2} d) m r^{2} \alpha

49. Where the value of g is greater?a) At polesb) At equatorc) A \& B bothd) None of the above

40. The sun exerts a forces of attraction on the planets for keeping them in theira) Axesb) Spin-motionc) Orbitsd) None of them

59. When an upward acceleration of an elevator is increased the weight of the body in it isa) Zerob) Further increasedc) Negatived) Constant

70. Which of the following is a relatively strong force in nature:a) Strong nuclear forceb) Electromagnetic forcec) Weak nuclear forced) Gravitational force

29. If we whirl a stone at the end of a string in the vertical circle it is likely to break when the stone is.a) At the highest pointb) At the lowest pointc) At any point during motiond) At the point where gravity is not acting

5. Radius of geo-stationary orbit form center of earth is nearly.a) 42000 \mathrm{~km} b) 36000 \mathrm{~km} c) 24000 \mathrm{~km} d) 18000 \mathrm{~km}

18. If a car moves with a uniform speed of 2 \mathrm{~ms}^{-1} in a circle of radius 0.4 . its angular speed is.a) 4 \mathrm{rad} \mathrm{s}^{-1} b) 5 \mathrm{rad} \mathrm{s}^{-1} c) 1.6 \mathrm{rad} \mathrm{s}^{-1} d) 2.8 \mathrm{rad} \mathrm{s}^{-1}

10. The circumference subtends an angle.a) \pi radianb) 2 \pi radianc) \pi / 2 radiand) 4 \pi radian

17. In case planets the necessary acceleration is provided by.a) Gravitational forceb) Frictional forcec) Coulomb forced) Centripetal force

6. According to Einstein the gravity interaction is possible between.a) Material objects onlyb) Material objects and electromagnetic radiation onlyc) Electromagnetic radiations.d) None of the above.

26. Angular speed of seconds hand of a watch in \mathrm{rad}^{-1} is.a) \pi b) \pi / 2 c) \pi / 30 d) \pi / 180

1. The rotational K.E of hoop is equal to the.a) Its translational K.Eb) Half than its translational K.Ec) Double than its translational K.Ed) Four times than its translational K.E

7. The period of a circular motion is given by.a) T=r V b) T=\omega w c) T=2 \pi \omega d) T=2 \pi / \omega

A gramophone record turntable accelerate from rest to an angular velocity of 45.0 rev \min ^{-1} in 1.60s. What is its average angular acceleration?

2. A hoop and disc have same mass and radius. Their rotational K.E are related by an equation.a) K . E_{\text {hoop }}=K . E_{\text {disc }} b) K . E_{\text {hoop }}=2 K . E_{\text {disc }} c) K . E_{\text {hoop }}=1 / 2 K . E_{\text {disc }} d) K . E_{\text {hoop }}=4 K . E_{\text {disc }}

63. Freely falling bodies are in a state ofa) Restb) Static equilibriumc) Dynamic equilibriumd) Weightlessness

54. At what depth below the earth surface the value of g reduces to one half of its value on the earths surfacea) R_{e} / 2 b) R_{e} / 4 c) R_{e} d) 2 R_{e}

23. A cyclist cycling around a circular racing track skids becausea) The centripetal force upon him is less than limiting frictionb) The centripetal force upon him is greater than limiting frictionc) The centripetal force upon him is equal to the limiting frictiond) The friction between the tyres of the cycle and road vanishes