Physics-6.UNIT 15– TEST SOLUTION

UNIT 15– TEST SOLUTION 1. (C) 2. (A) To convert galvanometer into voltmeter, we put the known resistance in series. 3. (D) The magnetic field at the center due to straight part of the conductor The magnetic field at the centre due to circular coil is Both fields are in opposite directions hence 4. (C) 5. (B) As we known according to Boit-Savart's law in vector form 6. (B) 7. (D) 8. (A) = 4x10–7 N/m 9. (B) 10. (B) 11. (A) 12. (D) 13. (C) R = 900 14. (D) 15. (D) 16. (D) Force of proton F = 17. (B) 18. (A) 19. (B) = 1.57 x 10–3 T 20. (C) 21. (B) 22. (B) = 8 x 10–5 Wb/m2 23. (A, B) The force on a charge q moving with a velocity v in a magnetic field B is given by F = q (v x B) Dimensions of B = = ML0T–1Q–1 = ML0T–2I–1 24. (B, D) B = Dimensions of = = = 25. (D) Refer to expression (12.6). If , this expression reduce to Thus . Hence the correct choice is (d). 26. (D) Since = = 27. (D) 28. (C) = 6.28 x 10–5 T. 29. (B) = 8 x10–8 T 30. (B)

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