# Machine Design Questions and Answers – Multi Leaf Spring

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This set of Machine Design Multiple Choice Questions & Answers (MCQs) focuses on “Leaf Spring”.

1. Bending stress in graduated length leaves are more than that in full length leaves.
a) Yes
b) No
c) In some cases
d) Can’t be stated

Explanation: Bending stress in full length leaves is around 50% higher than graduated length leaves.

2. Nip is the initial gap between extra full length leaf and the graduated length leaf before the assembly.
a) True
b) False

Explanation: Nipping is done to balance the bending stress in the full length leaf and graduated length leaf.

3. Nipping is defined as leaving the gap between full length leaf and graduated length leaf.
a) True
b) False

Explanation: Nipping is pre stressing achieved by a difference in radii of curvature.

4. A leaf spring consists of 3 extra full length leaves and 14 graduated length leaves. The maximum force that can act on the spring is 70kN and the distance between eyes of the spring is 1.2m. Width and thickness of the leaves are 100mm and 12mm respectively. If modulus of elasticity is 207000N/mm², calculate the initial nip.
a) 26.8mm
b) 24.9mm
c) 22.5mm
d) 23.1mm

Explanation: C=2PLᵌ/Enbtᵌ where L=1.2/2, n=3+14,P=70/2.

5. A leaf spring consists of 3 extra full length leaves and 14 graduated length leaves. The maximum force that can act on the spring is 70kN and the distance between eyes of the spring is 1.2m. Width and thickness of the leaves are 100mm and 12mm respectively. Calculate the initial pre load required to close the nip.
a) 4332.2N
b) 4674.1N
c) 4985.4N
d) Can’t be determined

Explanation: P=2x3x14x35000/17(3×3+2×14).

6. Belleville spring can be used in clutch application.
a) True
b) False

Explanation: When h/t=2.1, the Belleville spring can be used in clutches.

7. Belleville spring can only produce linear load deflection characteristics.
a) Only linear
b) Linear as well as non linear
c) Non-linear
d) None of the mentioned

Explanation: Beliville spring can provide any linear or non-linear load deflection characteristics.

8. When two Belleville sprigs are arranged in series, half deflection is obtained for same force.
a) One fourth deflection
b) Double deflection
c) Four time deflection
d) None of the listed

Explanation: Double deflection is obtained.

9. When two Belleville springs are in parallel, half force is obtained for a given deflection.
a) Half force
b) Double force
c) Same force
d) Can’t be determined

Explanation: Double force is obtained.

10. Propagation of fatigue failure is always due to compressive stresses.
a) Due to bending
b) Due to tensile
c) Due to fatigue
d) None of the listed

Explanation: Propagation is always due to tensile stresses.

11. The strain energy stored in a spiral spring is given by?
a) 12M²L/Ebtᵌ
b) 6M²L/Ebtᵌ
c) 8M²L/Ebtᵌ
d) None of the listed

Explanation: U=Mθ/2 where θ=12ML/Ebtᵌ.

Sanfoundry Global Education & Learning Series – Machine Design.
To practice all areas of Machine Design, here is complete set of 1000+ Multiple Choice Questions and Answers. 