IIT JEE – 2009 PHYSICS – PAPER & ANALYSIS:
IIT JEE is one of the toughest examinations in the world. In the year 2009 this exam was conducted in two parts, first was PAPER-1 and second was PAPER-2. There were 20 questions in PAPER-1 and 19 questions in PAPER-2 of each subject. Each paper was consisting of 60 and 57 questions respectively. Paper-1 and Paper-2 both were of 240 marks. This whole booklet is very useful from exam point of view. This booklet consists of three different parts.
Q. A ball is dropped from a height of 20 m above the surface of water in a lake. The refractive index of water is 4/3. A fish inside the lake, in the line of fall of the ball, is looking at the ball. At an instant, when the ball is 12.8 m above the water surface, the fish sees the speed of ball as
(A) 9 m/s (B) 12 m/s
(C) 16 m/s (D) 21.33 m/s
Q. A student performed the experiment of determination of focal length of a concave mirror by u – v method using an optical bench of length 1.5 meter. The focal length of the mirror used is 24 cm. The maximum error in the location of the image can be 0.2 cm. The 5 sets of (u, v) values recorded by the student (in cm) are: (42, 56), (48, 48), (60, 40), (66, 33), (78, 39). The data set(s) that cannot come from experiment and is (are) incorrectly recorded, is (are)
(A) (42, 56) (B) (48, 48)
(C) (66, 33) (D) (78, 39)
Ans. (C & D)
Q. If the resultant of all the external forces acting on a system of particles is zero, then from an inertial frame, one can surely say that
(A) linear momentum of the system does not change in time
(B) kinetic energy of the system does not change in time
(C) angular momentum of the system does not change in time
(D) potential energy of the system does not change in time
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