15. Magnetic fields at two points on the axis of a circular coil at a distance of 0.05m 0.2m from the centre are in the ratio 8: 1. The radius of coil is- (a) 0.15m (b) 1.0m (c) 0.1m (d) 0.2m 16. A student is performing the experiment of resonance column. The diameter of the column tube is 6cm. THE Frequency of the tuning fork is 504 Hz. Speed of the sound at the given temperature is 336m/s. The zero of the meter scale coincides with tip end of the resonance column tube. The reading of the water level in the column when the first resonance occurs is: (a) 14.8cm (b) 16.6cm 17. (c) 18.4cm (d) 13cm 18. Match List - I with List - II: List - I (a) h (Planck's constant) (b) E (kinetic energy) (c) V (electric potential) (d) P (linear momentum) List - II (i) [MLT-1 (ii) [MLT1] (iii) [MLT2] (iv) [ML] Choose the correct answer from the options given below: (a) (a) (i), (b) (ii), (c) (iv), (d) (iii) (c) (a)(ii), (b) (iii), (c) (iv), (d) (i) (b) (a)(iii), (b)(ii), (c)(iv), (d) (i) (d) (a)(iii), (b) (iv), (c) (ii), (d) (i) A proton, a deuteron and an a particle are moving with same momentum in a uniform magnetic field. The ratio of magnetic force acting on them is............and their speed is -- in the ratio. (a) 2:1:1 an 4:2:1 (b) 4 2 1 and 2:1:1 (c) 1:2:4 and 1:1:2 (d) 1:2:4 and 2:1 :1 19. Two satellites A and B of masses 200kg and 400kg are revolving round B the earth at height of 600km and 1600km respectively. If TA and TB are the time periods of A and B respectively then the value of TB - TA : [Given: radius of earth = 6400km, mass of earth = 6 1024 kg] E Acti Go to 20. (a) 3.33 x 10s (b) 1.33 x 102s (c) 4.24 x 10s (d) 4.24 x 10s An engine of a train, moving with uniform acceleration, passes the signal - post with velocity u and the last compartment with velocity v. The velocity with which middle point of the train passes the signal post is: u+v (a) 2 U+u V-U (b) (c) 2 2 v-u 2