Q-22 Q-19 Two vectors Ä and are at right angles to each other. when (A) Ä+É=O (C) ÄxÉ=O (B) Ä-É=O (D) Ä.É-O Q-20 If VI—Valand V.. is finite, then (A) VI is parallel to V, (C) V! and Va are mutually perpendicular (D) I 1 Q-21 A force F = (5i +3j)Newrton is applied over a particle which displaces it from its origin to th (2i — 15) metres. The work done on the particle is (C) +7 joules (B) +13 joules (A) — 7 joules Q22 The angle between tu'ovectors —2i+3j+É and +2j—4ü is (A) 00 (C) 1800 Q-23 The angle between the vectors (i + j) and i) is (A) 300 (C) 600 (B) 450 (D) +11 joules (D) None of the above (D) 900

Dear Student ,

-2i^+3j^+k^·i^+2j^-4k^=-2i^+3j^+k^i^+2j^-4k^cosθ-2+6-4=-2i^+3j^+k^i^+2j^-4k^cosθ0=-2i^+3j^+k^i^+2j^-4k^cosθcos θ=0θ=90°


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(B) 90
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