Daily Archives: November 19, 2020

Determine the blank diameter and the other drawing variables for the dies of all draws.

8.6 In a particular piercing operation, 20 mm holes are to be punched in a brass sheet of 3 mm thick. The

maximum shear strength of the sheet may be taken as 185 MPa. Design the punch and the die sizes as

well as the required punch force.

8.7 A cylindrical cup, 100 mm diameter and 85 mm deep, is to be drawn from a steel sheet of deep

drawing quality, 1 mm thick. Determine the blank diameter and the other drawing variables for the

dies of all draws. Also, estimate the drawing load if the tensile strength is 415 MPa.

Where are the following used?

8.23 How does the grain direction in sheet metal affect the design of:

(a) Bending dies (b) Blanking dies

8.24 Generally, the die opening is straight up to a certain length and tapered thereafter. Explain the reason

for such a shape.

8.25 In die shearing operations, die size is the hole size and punch size is the blank size. Explain the

validity of the above statement with supporting reasons.

8.26 Where are the following used?

(a) Rigid blank holder (b) Spring loaded blank holder

Explain the process of air carbon arc cutting.

9.82 Explain the process of air carbon arc cutting.

9.83 Explain the resistance welding process giving the equipment, parameters controlled and the

applications.

9.84 What are the parameters to be controlled in the resistance welding process?

9.85 Distinguish giving reasons, between joining of sheets in resistance welding and arc welding, from the

point of current required and duration of the welding.

1.5Show by a schematic sketch, a resistance welding operation labelling the important features.

Identify the correct statement among the following

11.2 Metal powder particle size is reduced during

atomisation by

(a) Decreasing gas velocity

(b) Increasing gas velocity

(c) Decreasing gas pressure

(d) Decreasing metal volume

11.3 Identify the correct statement among the

following:

(a) Blending and mixing refer to the same

process of mixing different types of

metal or alloy powders of different size

distributions

(b) Blending is mixing the different metal or

alloy powders of different size distributions

while mixing is mixing same types

of metal or alloy powders

(c) Blending is mixing the same metal or

alloy powders of different size distributions

while mixing is mixing different

types of metal or alloy powders

(d) Blending and mixing refer to the same

process of mixing same types of metal or

alloy powders of different size distributions

What is the function served by the fibres in a composite material?

14.6 What is the function served by the fibres in a composite material?

14.7 What is the difference between fibre and particle reinforced composites? Give an example.

14.8 Give a classification of composites based on the matrix material used.

14.9 Give a classification of composites based on the reinforcement material used.

14.10 What are the different types of fibres used in composites? How are their properties compared?

14.11 Write a short note on metal matrix composites.

Characteristics of sinus bradycardia include?

A. Sinus bradycardia

 

a. often occurs naturally.

b. is considered abnormal in athletes.

c. is often seen in Wolff–Parkinson–White syndrome.

d. is caused by increased sympathetic stimulation.

B.  Characteristics of sinus bradycardia include

a. PR intervals that change.

b. inverted P waves in lead II.

c. a regular rhythm.

d. wide, bizarre QRS complexes.

C. Sinus tachycardia

a. has mostly the same characteristics as normal sinus rhythm except that it

has a rate of greater than 120 beats per minute.

b. is produced by stimulation of the parasympathetic branch of the

autonomic nervous system.

c. may be caused by ingestion of caffeine or alcohol, smoking, or fever.

d. continues even after the stimulus causing it is removed.

Match the following sinus dysrhythmias with the correct description.

A.  With sinus arrest, the escape mechanism that follows the pause in electrical

 

activity may arise from the

a. SA node.

b. AV junction.

c. ventricles.

d. All of the above.

B. Match the following sinus dysrhythmias with the correct description.

C. Sinoatrial exit block occurs when the

a. impulse originating in the SA node is blocked from reaching the atria.

b. heart rate slows to less than 60 beats per minute.

c. heart rate speeds up and slows down in a cyclical manner.

d. heartbeat ceases completely.

D. Treatment for symptomatic bradycardia includes

a. vagal maneuvers.

b. atropine with a fluid bolus of 250 cc.

c. temporary or permanent pacing.

d. defibrillation.

Why is it important to check for a pulse when there are premature beats in the rhythm?

A. Why is it important to check for a pulse when there are premature beats in the rhythm?

B. Premature atrial complexes

a. are typically preceded by an inverted P9 wave.

b. are always followed by a compensatory pause.

c. have a wide and bizarre QRS complex.

d. may have normal P9R intervals.

C. Describe the effect that a PAC has on the regularity of the underlying

rhythm.

D.  In wandering atrial pacemaker, the pacemaker site shifts between the SA node, atria, and/or

a. Purkinje fibers.

b. ventricles.

c. AV junction.

d. bundle of His.

 

List the treatments for unstable SVT.

A. Your patient is a 67-year-old female with a history of cardiac problems. After

 

attaching her to the monitor, you see a slightly irregular rhythm with normal

QRS complexes, but each P9 wave is different. This rhythm is (LO 13.4)

a. frequent PACs.

b. sinus arrest.

c. sinus dysrhythmia.

d. wandering atrial pacemaker.

B. The heart rate characteristic of atrial tachycardia is __________ beats per

minute. (LO 13.5)

a. 60 to 100

b. 100 to 150

c. 150 to 250

d. 300 to 350 The QRS complexes seen with atrial tachycardia are normally __________

seconds in duration.

a. 0.06 to 0.10

b. 0.10 to 0.20

c. 0.12 to 0.20

d. 0.20 to 0.24

C. List the treatments for stable SVT.

D.  List the treatments for unstable SVT.

….

What dysrhythmia is the patient experiencing?

A. The atrial waveforms associated with atrial fibrillation are __________ and

 

the PR intervals are __________.

a. referred to as saw toothed; variable

b. indiscernible; nonexistent

c. inverted; less than 0.12 seconds

d. dissociated; between 0.12 and 0.20 seconds

B.  Which dysrhythmia is totally irregular?

a. Sinus bradycardia

b. 3rd-degree AV heart block

c. Ventricular tachycardia

d. Atrial fibrillation

C.  Atrial fibrillation has an atrial rate of __________ beats per minute.

a. between 40 and 60

b. between 100 and 150

c. between 250 and 350

d. greater than 350

D.  What dysrhythmia is the patient experiencing?

a. Accelerated junctional

b. Atrial fibrillation

c. Atrial flutter

d. Ventricular tachycardia