Title Physics ÔÇó Final Step-A ÔÇó VMC.pdf ✅

Vidyamandir Classes VMC | Final Step | Part - A 1 Class XI | Physics Final Step | Part - A | Physics Introduction to Vector & Forces CHOOSE THE CORRECT ALTERNATIVE. ONLY ONE CHOICE IS CORRECT. HOWEVER, QUESTIONS MARKED ‘*’ MAY HAVE MORE THAN ONE CORRECT OPTION. 1. Three non-zero vectors A B C , and    add up to zero. Find which is false? (A) ( ) A B C      is not zero unless B C,   are parallel (B) ( ) A B C      is not zero unless B C,   are parallel (C) If A,B,C    define a plane, ( ) A B C      is in that plane (D) 2 2 2 ( ) A B .C A B C C A B         2. When in going east at 10 kmph, a train moving with constant velocity appears to be moving exactly ‘north- east’. When my velocity is increased to 30 kmph east it appears to be moving north. With what speed should i move north so that train appears to be moving exactly south-east? (A) 30 (B) 20 (C) 50 (D) 10 3. A wedge of mass M rests on a smooth horizontal surface. It is placed against a smooth vertical wall as shown. A force F is applied to the inclined surface (i) horizontally (ii) vertically (iii)  to the inclined surface. (i) (ii) (iii) Let R be normal force between wall and block and N be normal force between ground and the block. Then for the three cases : (A) (i) R = F, N = Mg (B) (i) R = F, N = Mg (iii) F Mg sin R     (ii) R = 0, N = Mg + F F Mg cos N     (iii) R F sin , F Mg cos N      (iii) R F sin ,   N Mg F cos    (C) N = Mg for each case and R = F, 0 and mg sin (D) None of these 4. It is found that A B A .      This necessarily implies: (A) B  0   (B) A B,   are anti-parallel (C) A B,   are perpendicular (D) A B  0  
Vidyamandir Classes VMC | Final Step | Part - A 2 Class XI | Physics 5. Let there be two vectors a  and b  such that a b    is in same direction as a b    . Select the correct alternative. (A) a b   0    (B) | | | | a b    (C) Both (A) & (B) must be simultaneously true (D) a b. 0    6. If a  denotes a unit vector along an incident light, b  a unit vector along refracted ray into a medium having refractive index x (relative to first medium) and c  is a unit vector normal to boundary of two media and directed towards first medium , then law of refraction is (A) a c x b c . ( . )      (B) a c x b c    ( )     (C) c a x b c    ( )     (D) x a c b c ( )        7. If A  and B  are the components of C  , then : (A) 3 2 A C  (B) 2 C B  (C) 2 3 1 C A   (D) B C   2 3 1   *8. For two vectors A B, A B A B and          is always true when : (A) A B   0   (B) A B    (C) A B   0   and A B and   are parallel or anti parallel (D) Either A  or B  is zero *9. Regarding non-zero vectors, which of the following is a correct statement : (A) Two equal vectors can never give an addition resultant equal to null – vector. (B) Three non-coplanar vectors can not give zero vector addition resultant (C) If a b c .( ) 0      and | | | | | | a b c      then a b c      can never be a null vector (D) If a b   0    and | | | |, a b    then a b    can be zero vectors. 10. The friction coefficient between the board and the floor shown in figure is  . The maximum force that the man can exert on the rope so that the board does not slip on the floor is : (m is mass of man and M is mass of plank) (A)   1   M m g    (B)   1   M m g    (C) M g m  (D) None of these *11. A block of mass 4 kg is acted upon by a 50 N force a shown. The friction coefficient between block and wall is . (A) For  =0.5 block will be at rest (B) For   0 2. block will move down (C) For   0 8. block will move up (D) Block can never move up for any value of  A B C 45 30
Vidyamandir Classes VMC | Final Step | Part - A 3 Class XI | Physics 12. Given a parallelogram ABCD. If | AB | a, | AD | b &| AC | c       then DB AB .   has the value (A) 2 2 2 2 2 a b c   (B) 2 2 2 3 2 a b c   (C) 2 2 2 3 2 a b c   (D) 2 2 2 3 2 a b c   13. Two forces P and Q are in ratio P : Q = 1 : 2. If their addition resultant is at an angle 1 3 2 tan         to vector P, then angle between P and Q is : (A) 1 1 2 tan       (B) 45o (C) 30o (D) 60o *14. Consider a set of forces F , F 1 2   and F3  acting on a particle of mass 2 kg. Mark the correct options. (A) For F , F , F 1 2 3    2 3 4    particle can move with constant velocity (B) For F , F , F 1 2 3    1 3 5    particle can take an acceleration of 2 3m / s (C) For F , F , F 1 2 3    2 3 4    particle can take an acceleration of 2 5m / s (D) For F , F , F 1 2 3    2 3 4    particle can take an acceleration of 2 2m / s *15. An iron sphere weighing 10 N rests in a V shaped trough whose sides form an angle 60 as shown in figure. Case I Case II Case III (A) 10 R N A  and 0 RB  in case I (B) 10 R N A  and 10 R N B  in case II (C) 20 3 R N A  and 20 3 R N B        in case III (D) 10 R N A  and 10 R N B  in all three cases 16. If 1 ˆ ˆ ˆ a i j k , a.b     ˆ  and ˆ ˆ a b j k      then b  is : (A) ˆ ˆ ˆ i j k   (B) ˆ ˆ ˆ i j k   (C) ˆi (D) 2ˆi *17. A river is flowing with a speed of 1 km/hr. A swimmer wants to go to point ‘C’ starting from ‘A’. He swims with a speed of 5 km/hr, at an angle  w.r.t. the river. If AB = BC = 400 m. Then : (sin53 4 / 5)  x (A) The value of  is 53 (B) Time taken by the man is 6 min (C) Time taken by the man is 8 min (D) The value of  is 45 1 km/hr B C A  A B 60 A B 60 A B 60 60 60
Vidyamandir Classes VMC | Final Step | Part - A 4 Class XI | Physics 18. Let a b c , ,    be unit vectors such that a b c    0     which one of the following is correct (A) a b b c c a       0        (B) a b b c c a       0        (C) a b b c a c       0        (D) a b b c c a    , ,       are mutually perpendicular *19. A man is standing on a road and observes that rain is falling at angle 45 with the vertical. The man starts running on the road with constant velocity. It appears to him that rain is still falling at angle 45 with the vertical, with speed 2 2 m/s. Motion of the man is in the same vertical plane in which the rain is falling. Then which of the following statement(s) are true : (A) It is not possible (B) Speed of the rain relative to the ground is 2m/s (C) Speed of the man is 4 m/s (D) Speed of the rains is 2 2 m/s 20. If a b c , ,    are three unit vectors such that a b c    0,     then a b b c c a . . .         is equal to : (A) 1 (B) 3 (C) 0 (D) 3/2 21. In a given co-ordinate system, a vector quantity is given as ˆ ˆ A j k   3 4 .  In another co-ordinate system chosen arbitrarily, A  cannot be : (A) 5ˆi (B) 5 ˆj (C) 5 ˆ ˆ ( 3 ) 2 i j  (D) 5( ) ˆ ˆ i j  *22. Consider a system of vector a b c d     0      consider two cases Case 1 : a  3  , b  5  , c  6  Case 2 : a  1  , b  4  , c  7  Mark the correct alternative(s) (A) Minimum magnitude of d  in case 1 is 0 (B) Maximum magnitude of d  in case 1 is 14 (C) Minimum magnitude of d  in case 2 is 2 (D) Maximum magnitude of d  in case 2 is12 23. Which of the sets given below may represent the magnitudes of three vectors adding to zero ? (A) 2. 4, 8 (B) 4, 8, 16 (C) 1, 2, 1 (D) 0.5, 1, 2 24. Consider a system of two vector a  and b  changing with respect to time t .  0 2 8 ; ˆ ˆ a ti t j    2 2 ˆ ˆ b t i j    Mark the correct options. (A) The vectors will become parallel to each other at t = 4 s (B) The vectors will never become perpendicular to each other (C) The vectors will become perpendicular to each other at t = 1/4 s (D) The vectors will become parallel to each other at t = 2 s 25. A vector OA i  3ˆ  is rotated by an angle  about its starting point O in x-z plane in clockwise sense, as seen by an observer located at a point on +y axis. The new vector will be : (A) 3 3 ˆ ˆ cos i sin j    (B) 3 3 ˆ ˆ cos i sin k    (C) 3 3 ˆ ˆ cos i sin k    (D) 3 3 ˆ ˆ sin i cos k    26. Two cars are moving on two mutual perpendicular straight roads. Car a moves along east & towards the crossing with 1 10 .  ms At any instant it is 1500m away from the crossing. B at the same instant is 1800m away from the crossing and is moving towards the crossing with 1 15 . ms  When do they come closest ? (A) 109.3s (B) 129.2 s (C) 119.3s (D) 99.3 s