## Lakshya Education MCQs

Question: The efficiency of a screw jack is maximum, when (where α = helix angle, and φ = angle of friction.)
Options:
 A. α = 45° + φ/2 B. α = 45° - φ/2 C. α = 90° + φ D. α = 90° - φ

Earn Reward Points by submitting Detailed Explaination for this Question

## More Questions on This Topic :

Question 1. The overturning of a vehicle on a level circular path can be avoided if the velocity of vehicle is __________ √(gra/h)
1.     Less than
2.     Greater than
3.     Equal to
4.     None of these
Question 2. Efficiency of a screw jack is given by (where α = helix angle, and φ = angle of friction.)
1.     tan(α + φ)/tanα
2.     tanα/tan (α + φ)
3.     tan(α - φ)/tanα
4.     None of these
Question 3. Moment of inertia of a triangular section of base (b) and height (h) about an axis passing through its c.g. and parallel to the base, is
1.     bh3/4
2.     bh3/8
3.     bh3/12
4.     bh3/36
Question 4. Moment of inertia of a triangular section of base (b) and height (h) about an axis passing through its c.g. and parallel to the base, is
1.     bh3/4
2.     bh3/8
3.     bh3/12
4.     bh3/36
Question 5. The overturning of a vehicle on a level circular path can be avoided if the velocity of vehicle is __________ √(gra/h)
1.     Less than
2.     Greater than
3.     Equal to
4.     None of these