Question : The angle of elevation of the top of a tower from a point on the ground is 30° and moving 70 m towards the tower it becomes 60°. The height of the tower is:

Option 1: $10$ m

Option 2: $\frac{10}{\sqrt{3}}$ m

Option 3: $10\sqrt{3}$ m

Option 4: $35\sqrt{3}$ m

Question : Metal tea pots have wooden handles because:

Option 1: wood is bad conductor of heat

Option 2: it prevents electric shock

Option 3: it gives beauty to the pots

Option 4: it is hygenic

Question : Air is said to be saturated when -

Option 1: It contains the maximum content of water vapour.

Option 2: Its pressure is minimum.

Option 3: Its thickness is maximum.

Option 4: It blows over the barren land.

Question : Soap helps in better cleaning of clothes because:

Option 1: Soap acts like a catalyst

Option 2: It reduces the surface tension of the solution

Option 3: It gives strength to the solution

Option 4: It absorbs the dirt

Question : The surface tension of water on adding detergent to it:

Option 1: increases

Option 2: decreases

Option 3: no change

Option 4: becomes zero