NDA 2018 Paper 2 | Height and Distance Question 10 | Mathematics

If a flage-staff of 6m height placed on the top of a tower throws a shadow of $$2\sqrt 3 $$ m along the ground, then what is the angle that the sun makes with the ground?

60$$^\circ$$

45$$^\circ$$

30$$^\circ$$

15$$^\circ$$

NDA 2018 Paper 2

MCQ (Single Correct Answer)

+2.5

-0.83

A spherical balloon of radius r subtends an angle $$\alpha$$ at the eye of an observer, while the angle of elevation of it centre is $$\beta$$. What is the height of the centre of the balloon (neglecting the height of the observer) ?

$${{r\sin \beta } \over {\sin \left( {{\alpha \over 2}} \right)}}$$

$${{r\sin \beta } \over {\sin \left( {{\alpha \over 4}} \right)}}$$

$${{r\sin \left( {{\beta \over 2}} \right)} \over {\sin \alpha }}$$

$${{r\sin \alpha } \over {\sin \left( {{\beta \over 2}} \right)}}$$

NDA 2019 Paper 2

MCQ (Single Correct Answer)

+2.5

-0.83

A ladder 9m long reaches a point 9m below the top of a vertical flagstaff. From the foot of the ladder, the elevation of the flagstaff is 60$$^\circ$$. What is the height of the flagstaff?

16.7m

10.5m

13.5m

15m

NDA 2019 Paper 1

MCQ (Single Correct Answer)

+2.5

-0.83

The angle of elevation of a tower of height h from a point A due South of it is x and from a point B due East of A is y. If AB = z, then which one of the following is correct?

h² (cot²y $$-$$ cot²x) = z²

z² (cot²y $$-$$ cot²x) = h²

h² (tan²y $$-$$ tan²x) = z²

z² (tan²y $$-$$ tan²x) = h²

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