13. A galvanometer of resistance 50 ohm gives a full scale deflection when 3 mA current passes through it. The series resistance that is to be connected to convert it into a voltmeter of range 0 – 3 V is a) 500 Ωb) 950 Ωc) 1000 Ω d) 750 Ω 14. Two resistances 6Ω and 3Ω are connected in parallel and this combination is connected in series with a 4Ω resistance. This combination is powered by a voltage source of 12 V and zero internal resistance. The ratio of power dissipated between 6Ω resistance and4Ω resistance is a) 1:4b) 4:1c) 1:8d) 3:2Space for rough work AEE15vA515. Two charged particles of charge ratio 1:4 moving with same velocity enter a region of uniform magnetic field of strength B and get deflected and move along curves with equal radius R. The ratio of their masses is a) 4:1b) 2:1c) 1:4d) 1:2 16. When a charged particle moves in a region with electric field E = 3i N/C and magnetic field B = 5j T, the trajectory of the particle is a) circleb) parabolac) straight lined) helix 17. Two co-axial coils A and B of radius R1 and R2 carry equal amount of current but flowing in opposite direction. The net magnetic field produced at the centre of these coils is zero. The ratio of the current flowing in the coil A to current in coil B is a) R1 : R2b) R2 : R1c) (R2 / R1)2d) (R1 / R2)2 18. Which among the following is a desirable feature of a ferromagnet that can be used as core of a transformer? a) high hysteresis loss and low retentivityb) low hysteresis loss and high retentivityc) high coercive field and high retentivityd) low hysteresis loss and low retentivity 19. The phase difference between the current through the resistance and voltage across the resistance in a series LCR circuit is a) 180ob) 0oc) 90od) 45o 20. An object of size 10 cm is kept at a distance of 10 cm from a convex lens. If the focal length of the lens is 5 cm, the size of the image is a) 10 cmb) 20 cmc) 5 cmd) 15 cm

dheeraj reddy , 6 Years ago

Grade 12th pass