(21) . Imaginary Part of the multiplicative inverse of a number 6-5i is?
5/61
6/61
-5/61
None of these
(22) . If z - a is a factor of polynomial P(z), then P(a) is always?
(23) . Solve: A = [aij] be n square matrix If a2i = 0 for all j 1, 2, 3, …, n, then the matrix A is?
Regular
Diagonal
Singular
None of these
(24) . The centroid of a Wangle LMN with vertices L(1,1,1), M(3, 3, 3), N(5, 5, 5) is the point?
(3,3,3)
(2,2,2)
(25, 2.5, 2.5)
None of these
(25) . The projection of a vector a= i+j+k on anther vector b= 3jk+3k is?
2/√2
1/√2
3/√2
None of these
(26) . The work done by a force F = i+j+k in moving an object from a point p(1,1,1) to the point Q(1,2,2) is?
(27) . The moment about a point p(0, 0, 0) of the force F = 21-i-k applied at Q(1, 1,1) is?
3i-3j
3j+3j
3j-3k
None of these
(28) . The population of a city increases by 700 each year If the population grows to 25000 in five years. its initial populations was?
21000
21500
22000
None of these
(29) . The sum of the first seventy positive odd integers is?
4910
4920
4900
None of these
(30) . The sum of the first seventy positive even integers is?
4960
4970
4980
None of these