The natural frequency of free longitudinal vibrations is equal to (where m = Mass of the body, s = Stiffness of the body and $$\delta $$ = Static deflection of the body)

An undamped spring-mass system with mass m and spring stiffness k is shown in the figure. The natural frequency and natural period of this system are ω rad/s and T s, respectively. If the stiffness of the spring is doubled and the mass is halved, then the natural frequency and the natural period of the modified system, respectively, are

A

2ω rad/s and T/2 s

B

ω/2 rad/s and 2T s

C

4ω rad/s and T/4 s

D

ω rad/s and T s

Consider the following remarks pertaining to the irrotational flow: 1. The Laplace equation of stream function $\frac{{{\delta ^2}{\rm{\Psi }}}}{{\delta {x^2}}} + \frac{{{\delta ^2}{\rm{\Psi }}}}{{\delta {y^2}}} = 0$ must be satisfied for the flow to be potential. 2. The Laplace equation for the velocity potential $\frac{{{\delta ^2}{\rm{\varphi }}}}{{\delta {x^2}}} + \frac{{{\delta ^2}{\rm{\varphi }}}}{{\delta {y^2}}} = 0$ must be satisfied to fulfil the orate . of mass conservation i.e continuity equation.. Which of the above statements is/are correct?

A

1 only

B

Both 1 and 2

C

2 only

D

Neither 1 or 2

The natural frequency of free transverse vibrations due to a point load acting over a simply supported shaft is equal to (where $$\delta $$ = Static deflection of a simply supported shaft due to the point load)

A

$$\frac{{0.4985}}{{\sqrt \delta }}$$

B

$$\frac{{0.5615}}{{\sqrt \delta }}$$

C

$$\frac{{0.571}}{{\sqrt \delta }}$$

D

$$\frac{{0.6253}}{{\sqrt \delta }}$$

The natural frequency of free transverse vibrations due to uniformly distributed load acting over a simply supported shaft is (where $$\delta {\text{S}}$$ = Static deflection of simply supported shaft due to uniformly distributed load)

A

$$\frac{{0.4985}}{{\sqrt {\delta {\text{S}}} }}$$

B

$$\frac{{0.5615}}{{\sqrt {\delta {\text{S}}} }}$$

C

$$\frac{{0.571}}{{\sqrt {\delta {\text{S}}} }}$$

D

$$\frac{{0.6253}}{{\sqrt {\delta {\text{S}}} }}$$

The natural frequency of free torsional vibrations of a shaft is equal to (where q = Torsional stiffness of the shaft and $$I$$ = Mass moment of inertia of the disc attached at the end of a shaft)

A

$$2\pi \sqrt {\frac{{\text{q}}}{I}} $$

B

$$2\pi \sqrt {{\text{q}}I} $$

C

$$\frac{1}{{2\pi }}\sqrt {\frac{{\text{q}}}{I}} $$

D

$$\frac{1}{{2\pi }}$$

Consider the following statements in connection with deflection-type and null-type instruments: 1. Null-type instruments are more accurate than the deflection-type ones. 2. Null-type of instrument can be highly sensitive compared to a deflection-type instrument. 3. Under dynamic conditions, null-type instruments are less preferred to deflection-type instruments. 4. Response is faster in null-type instruments as compared to deflection-type instruments. Which of the above statements are correct?

A

1, 2 and 3

B

1, 2 and 4

C

1, 3 and 4

D

2, 3 and 4

Which of the following statements regarding static methods are correct?
1. Static methods are difficult to maintain, because you can not change their implementation.
2. Static methods can be called using an object reference to an object of the class in which this method is defined.
3. Static methods are always public, because they are defined at class-level.
4. Static methods do not have direct access to non-static methods which are defined inside the same class.

A

1 and 2

B

2 and 4

C

3 and 4

D

1 and 3

What is the monoisotopic and average mass of valine? Given data: Mass of the most abundant isotope of Carbon (C°)=12.0000, Mass of most abundant isotope of Hydrogen (H°)=1.0078, Mass of most abundant isotope of Oxygen (O°)=15.9949, Mass of most abundant isotope of Nitrogen (N°)=14.0031, The average mass of Carbon (C)=12.011, The average mass of Hydrogen (H)=1.008, The average mass of Oxygen (O)=15.999, The average mass of Nitrogen (N)=14.007.

A

99.068 and 99.2361

B

99.216 and 99.326

C

99.111 and 99.321

D

99.068 and 99.132

A simple spring-mass vibrating system has a natural frequency of $${{\text{f}}_{\text{n}}}.$$ If the spring stiffness is halved and the mass is doubled, then the natural frequency will become

A

$$\frac{{{{\text{f}}_{\text{n}}}}}{2}$$

B

$$2{{\text{f}}_{\text{n}}}$$

C

$$4{{\text{f}}_{\text{n}}}$$

D

$$8{{\text{f}}_{\text{n}}}$$

The natural frequency (in Hz) of free longitudinal vibrations is equal to

A

1/2π√s/m

B

1/2π√g/δ

C

0.4985/δ

D

all of the mentioned

The natural frequency of free longitudinal vibrations is equal to (where m = Mass of the body, s = Stiffness of the body and $$\delta $$ = Static deflection of the body)

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