# In a triangle ABC cos A / a  = cos B /b = cos C /c , then triangle ABC is =

1.  Right-angled

2.  Isosceles right-angled

3.  Equilateral

4.  Scalene

4

Equilateral

Explanation :
No Explanation available for this question

# The angle of elevation of a stationary cloud from a point 2500 m above a lake is 15° and from the same point the angle of depression of its reflection in the lake is 45°. The height (in meters) of the cloud above

1.  2500

2.  2500√2

3.  2500√3

4.  5000

4

2500&#8730;3

Explanation :
No Explanation available for this question

# The magnitude of the projection of the vector a = 4i - 3j + 2k on the line which makes equal angles with the coordinate axes is

1.  √2

2.  √3

3.  1/√3

4.  1/√2

4

&#8730;3

Explanation :
No Explanation available for this question

# If the vectors i - 2xj - 3yk and i + 3xj + 2yk are orthogonal to each other, then the locus of the point (x, y) is

1.  a circle

2.  an ellipse

3.  a parabola

4.  a straight line

4

a circle

Explanation :
No Explanation available for this question

# For any vector ,

1.

2.

3.

4.

4

Explanation :
No Explanation available for this question

# If the vectors AB = - 3i + 4k and AC = 5i - 2j + 4k are the sides of a triangle ABC, then the length of the median through A is

1.  √14

2.  √18

3.  √25

4.  √29

4

&#8730;18

Explanation :
No Explanation available for this question

# If |a-| =1 , |b-|=2 and the angle between a- and b- is 120o , then {(a-+3b-) X (3a--b-)}<

1.  425

2.  375

3.  325

4.  300

4

300

Explanation :
No Explanation available for this question

# Let v- = 2i- + j- - k- and u- = i- + 3k- . If u is any unit vector t

1.  1

2.  √10 + √6

3.  √59

4.  √60

4

&#8730;59

Explanation :
No Explanation available for this question

# A class has fifteen boys and five girls. Suppose three students are selected at random from the class. The probability that there are two boys and one girl is

1.  35/76

2.  35/38

3.  7/76

4.  35/72

4

35/76

Explanation :
No Explanation available for this question

1.  1/2

2.  7/15

3.  2/15

4.  1/3

4