A charge q of mass m enters a region of electric field E = -E) with a velocity voi+ijat origin. Find the x coordinate where the charge hits the x axis again. (Neglect effect of gravity) (a) vm Eq 2v m (b) Eq vm 2E09 3vm (d) 2E09 18. Distance travelled by linear scale of screw gauge during two full rotation of circular scale is 1mm and circular scale has 50 divisions. In an experiment to measure thickness of a plate, six divisions of main scale are clearly visible and 28th division of circular scale coincides with reference line. Moreover when studs touch each other, zero of circular scale lies 4 division below the reference line, thickness of the plate will be: (a) 3.28 mm (b) 2.74 mm (c) 3.32 mm (d) 3.24 mm 19. A car goes on a circular horizontal road of radius 100 m. What should be the minimum coefficient of friction between the tyres and the road so that it completes the circle with velocity 10 m/s without slipping? (Take g = 10 m/s)g (a) 0.1 (b) 0.2 (c) 0.15 (d) 1 20. Three thin rods of mass m and length a each are joined to form a triangle ABC in vertical plane. The triangle is pivoted at the vertex A such that it can rotate in the vertical plane. It is released from rest when the side AB is horizontal as shown. As the triangle rotates, the maximum velocity of the vertex B, VMAX, is given by: A B C 4ga 2ga (a) vMAX 3 (b) vMAX = 3ga (c) vMAX = (d) v MAX= 5% ga