Questions

Black  surfaces are good emitters of heat ( They are also good absorbers of heat). If the black surface is rough too, the emitting will be better. So (b) is the correct answer. Shining surfaces reflect back radiation. So if the black surface is also shining the effectiveness of emitting heat is lessened.

Asbestos can cause

•  Lungs

• Gastrointestinal tract  types of Cancer.

Benzene can cause

• Leukemia

• Hodgkin's lymphoma types of Cancer.

Cadmium can cause

• Prostate type of Cancer.

A Hole gets bigger and bigger as you take more away from it.

Key Challenges of s/w testing:

1. Testing considered late in project

2. Requirements not testable

3. Integration is done after all components have been developed: This might result into full testing not being covered.

4. Complete testing is not possible

without this centripetal force, circular motion is not possible. It acts radially towards the centre and if this force is removed there will be no circular motion but the revolving body will fly off at a tangent.