Tag: science & technology

Quizzes (551) Questions (11015)

Questions Related to science & technology

Multiple choice general knowledge science & technology

If two gears are transmitting power of 10 HP at 1000 RPM. Module of first is 4.5 then what the module of the second gear ?

  1. 10 / 2 x pi x 1000

  2. 4.5 x (10/(2 x pi x 1000)

  3. 4.5

  4. 1/4.5
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

For two gears to mesh properly and transmit power, they must have the same module (a parameter defining gear tooth size). The module is inversely related to the diametral pitch and is a fundamental design parameter. If two gears are in mesh, their modules must be identical regardless of the power transmitted or rotational speed. The power (10 HP) and speed (1000 RPM) are irrelevant for determining the module of the second gear.

Multiple choice general knowledge science & technology

What is the maximum carbon percentage in a steel?

  1. 0.2%

  2. 2%

  3. 6%

  4. 20%
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Steel is defined as an alloy of iron and carbon with carbon content typically between 0.02% and 2% by weight. The 2% upper limit is a critical distinguishing factor between steel and cast iron (which has higher carbon content, typically 2-4%). Beyond 2% carbon, the material is classified as cast iron, not steel. Options A (0.2%) is too low for most steels, C (6%) and D (20%) are in the cast iron range.

Multiple choice general knowledge science & technology

If a cantilever beam of length 200 mm is subjected to load of 50 N at a distance of 120 mm from the fixed end of the beam. What is the maximum bending stress developed if section modulus is Zc?

  1. 50/ (120 x Zc)

  2. 50 x 80 / Zc

  3. 50 x 120 x Zc

  4. 50 x 120/Zc
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

For a cantilever beam, maximum bending stress occurs at the fixed end where bending moment is maximum. The bending moment M at the fixed end equals the load multiplied by the distance from the fixed end: M = 50 N x 120 mm. Bending stress is given by sigma = M/Zc, where Zc is the section modulus. Therefore sigma = (50 x 120)/Zc. Option A incorrectly uses the denominator format, option B uses the wrong moment arm (80 mm would be the distance to the free end), and option C incorrectly multiplies by Zc instead of dividing.

Multiple choice general knowledge science & technology

What is the meaning of endurance limit of the material?

  1. It is ultimate tensile strength of the material

  2. It is the limiting stress, below which material can withstand infinite numbeer of cylic loads without failure

  3. It is the minimum permanent deflection caused by the material when it is subjected to 1 million stress reversals

  4. It ration of ultimate strength to yield stregth
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

The endurance limit (or fatigue limit) is the maximum stress level below which a material can endure an infinite number of load cycles without failure. This is a critical concept in fatigue design for components subjected to repeated loading.

Multiple choice general knowledge science & technology

A person travels 12 km due North, then 15 km duo East, after that 15 km due West and then 18 km due South. How far is he from the starting point"?

  1. 6 km

  2. 12 km

  3. 33 km

  4. 60 km
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Starting from origin (0,0): North 12 km → (0,12), East 15 km → (15,12), West 15 km → (0,12), South 18 km → (0,-6). Final position is (0,-6), which is 6 km from starting point. The east and west movements cancel out completely.

Multiple choice general knowledge science & technology

If a hole in a disc is 10 mm +0.050 and -0.020 what should be the shaft dimension which will have minimum clearance of 0.018 mm and maximum clearance of 0.110 mm?

  1. 9.870 and 10.032

  2. 9.982 and 9.890

  3. 9.870 and 9.962

  4. 9.940 and 9.962
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Hole: 10mm (+0.050, -0.020) = 9.980 to 10.050 mm. For clearance 0.018 to 0.110 mm: Shaft max = Hole max - 0.018 = 10.050 - 0.018 = 10.032, Shaft min = Hole min - 0.110 = 9.980 - 0.110 = 9.870. But this doesn't match any option. Rechecking with shaft dimensions: Option D (9.940 to 9.962) gives clearance range of (9.980-9.962=0.018) to (10.050-9.940=0.110), which matches requirements.

Multiple choice general knowledge science & technology

In the context of genetic disorders, consider the following : A woman suffers from colour blindness while her husband does not suffer from it. They have a son and a daughter. In this context, which one of the following statements is most probabl) correct ?

  1. Both children suffer from colour blindness.

  2. Daughter suffers from colour blindness while son does not suffer from it.

  3. Both children do not suffer from colour blindness.

  4. Son suffers from colour blrndness while daughter does not suffer from it.
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Color blindness is X-linked recessive. A color-blind woman (XcXc) passes one Xc to son (making him XcY - affected) and one Xc to daughter (making her XcX, where X is normal father's X). Daughter is a carrier but not affected, while son is affected. This is because males have only one X chromosome.