## Kumar Ketan is teaching live on Unacademy Plus

ne

26.4k views 4.9 unacademy Kumar Ketan #16 Educator in IIT JEE #6 years teaching experience #IT JEE Physics #YouTuber (150k+ subs) #Unacademy educator(25kt lifetimeviews) #Under graduate topper Follow me on the Unacademy Learning App 1.3k 2 26 Followers Following Courses Get updates about new courses Watch all my lessons .Download slides and watch offline Lists (1) Kumar Ketan HINDI IIT JEE Physics by Kumar Ketan for lIT JEE 8 4 saves Kumar Ketan

IIT JEE 2017 PHYSICS Q. #1 to Q. #30 INDIAN IAN INSTITUTE Complete Paper Solution

Question 3 A body of mass m -10 kg is moving in a medium and experiences a frictional force F -kv2. Its initial speed is vo- 10 ms-1. If, after 10 s, its energy is 1/8mvo2 the value of k will be (1) 10-3 kgm-1 (2)10-3 kgs1 (3) 10-4 kgm1 (4 10-1 kgm-1s-1

2 4 to f 0 1812 12 Vo-2 k, k

Question4 A time dependent force F- 6t acts on a partice of mass 1 kg, f the particle starts from rest, the work done by the force during the first 1 second will be (1) 4.5 J (2) 22 J (3) 9 J (4) 18J

dv dt Sol. 6 1. t2 2 3 ms-1 2

Question 5 The moment of inertia of a uniform cylinder of length ( and radius R about its perpendicular bisector is I. What is the ratio e /R such that the moment of inertia is minimum? 1/3 2 (3) 1 N/2

3 32-32 2 2 3

Question 6 A slender uniform rod of mass M and length l is pivoted at one end so that it can rotate in a vertical plane (see figure). There is negligible friction at the pivot. The free end is held vertically above the pivot and then released. The angular acceleration of the rod when it makes an angle with the vertical is 3g sin 20 2g 3t (2) in 3g 2g -cos 20 (4) COs6 30 (3)

Question 7 The variation of acceleration due to gravity g with distance d from centre of the earth is best represented by (R Earth's radius):

Question 8 A copper ball of mass 100 gm is at a temperature t. It is dropped in a copper calorimeter of mass 100 gm, filled with 170 gm of water at room temperature. Subsequently, the temperature of the system is found to be 75 C. T is given by: (Given : room temperature 30 C, specific heat of copper 0.1 cal/gm C) (1) 800 C (2) 885 C (3) 1250 C (4) 825 C

V K _3 AV Vo

Question 10 Cpand Cp are specific heats at constant pressure and constant volume respectively. It is observed that Cp - Cp- a for hydrogen gas and Cp C-b for nitrogen gas. The correct relation between a and b is 14 (2) ab (3) a - 14b (4) a - 28b

Sol. Let molar heat capacity at constant pressure Xp and molar heat capacity at constant volume X -q- pM For hydrogen; a = For N2; b = 2 28 = 14 a= 14bl