Deck 4: Bonding Theory, Springs, and Flywheels

Question 1

In which of the following bonding theory, water molecules break down to form H+ and OH- ions?

A)electrostatic bonding theory
B)hot strength theory
C)surface tension theory
D)block and wedge theory

Answer 1

electrostatic bonding theory

Question 2

What does the clay particle absorb in electrostatic bonding theory?

A)complete water
B)h+ ions
C)oh-ions
D)sand grains

Answer 2

oh-ions

Question 3

For bonding action of clays, what is the amount of water needed?

A)1.5%-8%
B)3.5%-11%
C)4.5%-12%
D)5.5%-13%

Answer 3

1.5%-8%

Question 4

What is the amount of sea coal needed in cast irons for large green casting moulding sands?

A)10%
B)15%
C)20%
D)25%

Question 5

Pitch maybe used up to what percent?

A)1%
B)2%
C)3%
D)4%

Question 6

Which of the following increases the dry strength of the sand?

A)iron oxides
B)fuel oils
C)cereals
D)dextrin and molasses

Question 7

Cereals improve flowability and lower collapsibility.

Question 8

How much should fuel oil be added to increase the moulding ability of sand?

A)0.01% - 0.1%
B)0.02% - 0.2%
C)0.03% - 0.3%
D)0.04% - 0.4%

Question 9

Which of the following function can the spring perform?

A)store energy
B)absorb shock
C)measure force
D)all of the mentioned

Question 10

The helix angle is very small about 2?. The spring is open coiled spring.

A)yes
B)it is closed coiled spring
C)that small angle isn't possible
D)none of the listed

Question 11

The helical spring ad wire of helical torsion spring, both are subjected to torsional shear stresses.

Question 12

Multi leaf springs are not recommended for automobile and rail road suspensions.

Question 13

The spring index is the ratio of wire diameter to mean coil diameter.

Question 14

If spring index=2.5, what can be concluded about stresses in the wire?

A)they are high
B)they are negligible
C)they are moderate
D)cannot be determined

Question 15

A spring with index=15 is prone to buckling.

Question 16

If number of coils are 8 and wire diameter of spring 3mm, then solid length is given by?

A)none of the listed
B)27mm
C)24mm
D)21mm

Question 17

Compressed length is smaller than the solid length.

Question 18

Pitch of coil is defined as axial distance in compressed state of the coil.

A)yes
B)it is measured in uncompressed state
C)it is same in uncompressed or compressed state
D)none of the listed

Question 19

The maximum fluctuation of speed is the

A)difference of minimum fluctuation of speed and the mean speed
B)difference of the maximum and minimum speeds
C)sum of the maximum and minimum speeds
D)variations of speed above and below the mean resisting torque line

Question 20

In a turning moment diagram, the variations of energy above and below the mean resisting torque line is called

A)fluctuation of energy
B)maximum fluctuation of energy
C)coefficient of fluctuation of energy
D)none of the mentioned

Question 21

The ratio of the maximum fluctuation of energy to the ……. is called coefficient of fluctuation of energy.

A)minimum fluctuation of energy
B)workdone per cycle
C)maximum fluctuation of energy
D)none of the mentioned

Question 22

Due to the centrifugal force acting on the rim, the flywheel arms will be subjected to

A)tensile stress
B)compressive stress
C)shear stress
D)none of the mentioned

Question 23

The cross-section of the flywheel arms is usually

A)elliptical
B)rectangular
C)i-section
D)l-section

Question 24

In order to find the maximum bending moment on the arms, it is assumed as a

A)simply supported beam carrying a uniformly distributed load over the arm
B)fixed at both ends
C)cantilever beam fixed at the hub and carrying a concentrated load at the free end of the rim
D)none of the mentioned

Question 25

The diameter of the hub of the flywheel is usually taken

A)equal to the diameter of the shaft
B)twice the diameter of the shaft
C)three times the diameter of the shaft
D)four times the diameter of the shaft