# Automotive Engine Components Design Questions and Answers – IC Engine – Side Crankshaft at Angle of Maximum Torque

This set of Automotive Engine Components Design Interview Questions and Answers for freshers focuses on “IC Engine – Side Crankshaft at Angle of Maximum Torque”.

1. In the formula sinΦ=$$\frac{sin⁡θ}{(l/r)}$$, what is Φ?
a) The angle of inclination of the crankshaft with the line of action
b) The angle of inclination of connecting rod with the line of action
c) The angle of inclination of the crankshaft with the line of dead centers
d) The angle of inclination of connecting rod with the line of dead centers

Explanation: In the formula sinΦ=$$\frac{sin⁡θ}{(l/r)}$$, Φ is the angle of inclination of connecting rod with the line of dead centers and ϴ is the angle of inclination of the crank with a line of dead centers.

2. In the formula sinΦ=$$\frac{sin⁡θ}{(l/r)}$$, what is ϴ?
a) The angle of inclination of connecting rod with a line of dead centers
b) The angle of inclination of the crank with a line of action
c) The angle of inclination of the crank with a line of dead centres
d) The angle of inclination of the crank with connecting rod

Explanation: In the formula sinΦ=$$\frac{sin⁡θ}{(l/r)}$$, Φ is the angle of inclination of connecting rod with the line of dead centers and ϴ is the angle of inclination of the crank with a line of dead centres.

3. In the reaction (R1)v, what does v represent?
a) Reaction on the central plane
b) Reaction on a horizontal plane
c) Reaction on a vertical plane
d) The horizontal and vertical plane

Explanation: In the reaction (R1)v, where R1 is the reaction at bearing 1 and v represents the reaction of the bearing 1 in the vertical component.

4. Calculate the bending moment, when Pt=47900N and lc=170mm?
a) 8143KN-mm
b) 5983KN-mm
c) 9075KN-mm
d) 4578KN-mm

Explanation: Mb=Pt×lc
=47900×170
=8143KN-mm

5. Calculate the length of the bearing when the diameter of the crankpin is 150?
a) 377mm
b) 262.5mm
c) 938.7mm
d) 654.27mm

Explanation: l1=1.75dc
=1.75×150
=262.5mm
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6. In the formula l1=1.75dc, what is dc?
a) Diameter of bore
b) The diameter of the connecting rod
c) The diameter of crankpin
d) Diameter of piston

Explanation: In the formula l1=1.75dc, l1 is the length of the crankpin and dc is the diameter of the crankpin, generally d is always used to represent diameter.

7. Calculate the length of crankpin when the diameter of crankpin is 150?
a) 120mm
b) 178mm
c) 210mm
d) 160mm

Explanation: lc=0.8dc
= 0.8×150
= 120mm

8. In the formula c={$$\frac{l_1}{2}+t+\frac{l_2}{2}+m$$}, what is t?
a) Diameter of piston
b) The diameter of the connecting rod
c) Diameter of bore
d) Width of flywheel

Explanation: In the formula c={$$\frac{l_1}{2}+t+\frac{l_2}{2}+m$$}, l1 is the length of the bearing 1, l2 is the length of the bearing 2, t is the width of flywheel and m is the excess part of crankshaft known as margin.

9. Calculate the tangential component, where Pq=71260N, Φ=7.32, ϴ=35?
a) 21878N
b) 18979N
c) 47977N
d) 18978N

Explanation: Pt=PqSin(ϴ+Φ)
= 71260×sin (35+7.32)
= 47977N

10. Calculate the radial component, where Pq=71260N, Ф=7.32, ϴ=35?
a) 89173.7N
b) 52689.3N
c) 21938.8N
d) 91732.18N

Explanation: Pr= Pqcos(ϴ+Φ)
= 71260×cos (35+7.32)
= 52689.3N

11. Find the symmetry reactions R1 and R2 when load acting is 10KN?
a) 12873N and 7178N
b) 5000N and 6000N
c) 9138N and 21876N
d) 6000N and 12000N

Explanation: r1=r2=$$\frac{W}{2}$$
=$$\frac{10000}{2}$$
=5000N

12. Which are the two stresses that act inside crankshaft?
a) Shear and bending stress
b) Compressive and bending stress
c) Tensile and compressive stress
d) Compressive and shear stress

Explanation: Compressive and bending stress are the two stresses that act inside crankshaft and two resist these two stresses a reactive force R1 and R2 are produced.

13. Which of the mentioned below is the formula for total compressive stress?
a) A+B=C
b) (σc)tcb
c) τcab
d) ρ=ω+σ

Explanation: (σc)tcb is the formula for total compressive stress, always stress is represented by σ and shear stress is represented by τ. Hence, (σc)tcb is the right answer.

14. Which of the mentioned below is the equation of resultant bending moment?
a) τ=$$\sqrt{(\eta_b)v^2+(\rho_b)h^2}$$
b) Mb=$$\sqrt{(M_b)v^2+(M_b)h^2}$$
c) ω=$$\sqrt{(M_b)v^2+(M_b)v^2}$$
d) Mb=$$\sqrt{(\omega_b)v^2+(\omega_b)h^2}$$

Explanation: Mb=$$\sqrt{(M_b)v^2+(M_b)h^2}$$ is the equation of the resultant bending moment. Always resultant is the addition of horizontal and vertical components, and Mb represents the bending moment.