# UPSC Physics

11. A car moving on a horizontal road may be thrown out of the road is taking a turn

by the gravitational force | due to the lack of proper centripetal force | due to the lack of frictional force between the tire and the road | due to the reaction of the ground |

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12. A car of mass 1000 kg moves on a circular road with a speed of 20 m/s. Its direction changes by 90° after traveling 628 m on the road. The centripetal force acting on the car is

500 N | 1000 N | 1500 N | 2000 N |

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13. A car of mass 800 kg moves on a circular track of radius 40 m. If the coefficient of friction is 0.5, then maximum velocity with which the car can move is

7 m/s | 14 m/s | 8 m/s | 12 m/s |

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14. A car sometimes overturns while taking a turn. When it overturns, it is

the inner wheel which leaves the ground first | the outer wheel which leaves the ground first | both the wheel leave the ground simultaneously | either inner wheel or the outer wheel leaves the ground |

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15. A coin kept on a rotating gramophone disc just begins to slip if its centre is at a distance of 8 cm from the centre of the disc. The angular velocity of the gramophone disc is then doubled. Through what distance, the coin should be shifted towards the centre, so that the coin will just slip

2 cm | 4 cm | 6 cm | 16 cm |

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16. A cyclist goes round a circular path of circumference 343 m in s. The angle made by him, with the vertical is

42° | 43° | 44° | 45° |

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17. A cyclist turns around a curve at 15 miles per hour. If he turns at double the speed, the tendency of overturn is

doubled | quadrupled | halved | unchanged |

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18. A fighter aeroplane flying in the sky dives with a speed of 360 km/hr in a vertical circle of radius 200 m. Weight of the pilot sitting in it is 75 kg. What will be the value of force with which the pilot presses his seat when the aeroplane is at highest position (g = 10 m/s2)

3000 N | 1500 N | (75 × g)N | 300 N |

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19. 512 calories of radiation is incident on a body. It absorbs 220 calories the coefficient of emission is

0.43 | 0.57 | 1.7 | 0.34 |

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20. Heat energy received by the earth from the sun is due to

Convection | Radiation | Reflection of light | Transmission of light |

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