MATH & SCI. TEST 1

Which one of the following is useful friction ?

• Rings in cylinders

• Crankshaft bearings

• Brake shoe linings

• Wheel hole bearings

Which is in between the wheels and road, if vehicles are able to run on roads ?

• erosion

• motion

• corrosion

• friction

Which direction of motion frictional force acts ?

• equal

• opposite

• inclined

• forward

Determine the co-efficient of friction() between brass and steel when a brass slider was placed on the horizontal steel surface until it is just moving, if brass slides (W) = 3 Kgf Brass slides (W) = 3 Kgf Force (F) required = 0.7 kgf

• 0.033

• 0.133

• 0.233

• 0.333

Which is necessary to avoid production of heat ?

• sand

• coolant

• lubricant

• salt

Which is using for reduce the friction ?

• lubricants

• sand

• coal

• coolant

Centre of gravity is usually located where ?

• more weight is concentrated

• less weight is concentrated

• less mass is concentrated

• more mass is concentrated

Centre of gravity of an object depends on it's ?

• weight

• mass

• density

• shape

A simple method to find centre of gravity of a body is usage of . . . . . . . . . .

• stop watch

• plumbline

• pendulum

• screw gauge

The process of changing the structure of a metal by heating and cooling is ?

• Heat treatment

• Machining

• Hot rolling

• Melting