# ISRO Question Papers with Answers 2020 | ISRO ME Paper Set-C

ISRO Question Papers with Answers 2020 | ISRO ME Paper Set-C

## Question 11:

The ratio of maximum shear stress to average shear stress in a beam of rectangular section is

(a) 5.1

(b) 2/3

(c) 3/2

(d) 1.0

Ans: (c)

## Question 12:

A massless beam has a loading pattern shown in figure. Find the bending moment at mid span?

(a) 1 kN-m

(b) 3 kN-m

(c) 2 kN-m

(d) 0.0 kN-m

Ans: (a)

## Question 13:

Steel machine element at the critical section is in biaxial stress state with two principal stress being
300 N/mm2 and 300 N/mm2 (equal magnitude). Find the von Mises stress (in N/mm2) in the
member.

(a) 212.1

(b) 600

(c) 424.2

(d) 300

Ans: (d)

## Question 14:

A machine component of 90 kg mass needs to be held in position using three springs as shown
below. The spring constants K1, K2 and K3 are 4, 4 and 8 N/m respectively. Find the natural
frequency of the system in rad/sec.

(a) 0.33

(b) 0.42

(c) 0.13

(d) 3.0

Ans: (a)

## Question 15:

If, Kf is the fatigue stress concentration factor and Kt is the theoretical stress concentration factor
then, the notch sensitivity q is?

(a) (Kf + 1)/(Kt + 1)

(b) (Kf – 1)/(Kt – 1)

(c) (Kt – 1)/(Kf + 1)

(d) (Kf – 1)/(Kt + 1)

Ans: (b)

## Question 16:

Beach or clamshell marks on a failed metallic surface are typical of

(a) Ductile fracture

(b) Brittle fracture

(c) Creep failure

(d) Fatigue failure

Ans: (d)

## Question 17:

In vibration isolation if ω/ωn is less than 2 then the transmissibility will be

(a) Less than one

(b) Equal to one

(c) Greater than one

(d) Zero

Ans: (c)

## Question 18:

The natural frequency of a simply supported beam of length l with mass M at its centre, flexural
rigidity EI and negligible beam mass is

Ans: (a)

## Question 19:

A machine component of natural frequency 20 rad/s is subjected to a base motion from the
machine which is harmonic in nature with amplitude 3 m/s2 at 10 rad/s. What is the peak amplitude of relative displacement of the components if the damping is negligible?

(a) 0.1 mm

(b) 1.0 mm

(c) 10.0 mm

(d) 100.0 mm

Ans: (c)

## Question 20:

In a shower mixer, cold water at 27 deg C, flowing at 5 kg/min is mixed with hot water at 77 deg C
flowing at 15 kg/min. The exit temperature of the mixture is

(a) 45.4 deg C

(b) 64.5 deg C

(c) 34.5 deg C

(d) 68.4 deg C

Ans: (b)