Are These Physics Multiple Choice Answers Correct?

Click For Summary

Homework Help Overview

The discussion revolves around multiple choice questions related to various physics concepts, including angular momentum, forces in circular motion, thermodynamics, fluid dynamics, and wave mechanics. Participants are checking the correctness of their selected answers from an exam.

Discussion Character

  • Exploratory, Assumption checking, Conceptual clarification

Approaches and Questions Raised

  • Participants share their selected answers along with reasoning for each question. Some express uncertainty about specific answers and seek validation from others. Questions arise regarding the nature of central forces and their components.

Discussion Status

Some participants provide feedback on the answers and reasoning presented, while others express confusion or seek clarification on particular concepts. There is an ongoing exploration of the correctness of the answers, with no explicit consensus reached.

Contextual Notes

Participants are working within the constraints of a homework assignment, which may limit the depth of discussion. There are indications of differing interpretations of concepts, particularly regarding the nature of central forces.

abrowaqas
Messages
113
Reaction score
0

Homework Statement



Somebody please check my multiple choice questions, I have attempted in my exam.
The capital letter is the answer that I have ticked in the exam.


Homework Equations





The Attempt at a Solution



1. The angular momentum of a particle under the influence of a central force is
a) Infinite b) Negative c) ZERO d) Constant
reason: bcoz angular momentum is always act externally.

2. Transverse component of the central force acting on a particle to keep it moving along a path is
a) Mv2r b)mv2/r c) ZERO d) constant
reason: bcoz there is no transverse component of velocity

3. Law of Intertia can be defined in
a) Accelerated system b) NON ACCELERATED SYSTEM c) both a) & b) d)None of these
reason: Newtons laws are only valid in non accelerated system

4. The K.E of the particle executing a uniform circular motion:
a) Increases b) decreases c) REMAINS SAME d)None of these
reason: k.E = .5 mv2. since m is const and v is also uniform hence no change in k.E

5. What type of force acts on a raindrop to reduce its speed?
a) Gravitational force b) FORCE OF FRICTION c) Electromagnetic force d) drag force


6. The branch of heat relating to the measurement of temperature of body is called
a) THERMOMETRY b) photometry c) ellipsometry d) calorimetry


7. Which type of ideal gas will have the largest value for Cp-Cv
a) MONOATOMIC b) diatomic c) polyatomic d) the value is same for all
reason: it was an educated guess.

8. What would be the most likely value for Ct, the molar heat capacity at constant temperature
a) Zero b) zero<Ct< Cv c) CV<CT<CP d) Ct= infinite

reason: here answer is C. it was a guess.
9. For which of the following process the entropy changes zero?
a) Isobaric b) isothermal c) ADIABATIC d) isochoric
reason: since no heat loss and gain in adiabatic so entropy changes zero. coz entropy = Q/T

10. The zeroth law of thermodynamics helps to define the term
a) TEMPERATURE b) pressure c) volume d) density

11. The law of conservation of mass in fluid dynamics can be expressed as
a) Av= constant b) RHO AV= CONSTANT c) P+(1/2)rho V + rho gy = constant d)None of these
reason: law of continuity of fluids flow.

12. The SI Unit of Viscosity is
a) N-S/M2 b) Dynes-s/cm2 c) N-s/m dynes-s/cm

reason: the answer is a.

13. The equation of the continuity requires that the total mass within certain volume must remain constant:
a) If there are sources as well as sinks
B) IF THERE ARE NO SOURCES & SINKS
c) If there are sources only
d) If there are sinks only
reason: its a guess.

14. If the length of the “L” and the total force acting on it is “F” then surface tension given is
a) F*L b)F.L C) F/L d) L/F
reason: the answer is C.

15. If the particle of liquid which pass through a certain point do not follow the same path, as that followed by the particles that passed the same point previously the liquid is said to have
a) STEADY b) Non steady flow c) turbulent flow d)None of these

16. The potential energy of a simple harmonic oscillator is
a) –Kx b) –Kx2 c) 0.5 Kx2 D) -.5KX2

reason: The answer is d. bcoz the direction of SHO is always pointing towards origin

17. Types of the mechanical weaves are
a) Longitudinal and transverse waves
B) SOUND AND RADIO WAVES
c) Longitudinal and transverse waves
d) Transverse & x-rays

18. The refracted ray bends towards the normal when it enters from
A) RARE TO DENSER MEDIUM
b) denser to rare medium
c) Air to vacuum
d) None of these

19. On a reflection from a fixed end, a transverse wave undergoes a phase change of___ degrees
a) 90 b) 180 c) 270 d) 360
reason: the answer is 180. then sin function changes every 180 of phase difference

20. Resolving power of a gratting can be written as:
a) LAMBA/DEL LAMDA b) del theta/del lamda c) del lamda/lamda d) del lamda/del theta

reason: the answer is a.
 
Physics news on Phys.org
Here's my 2 cents.

abrowaqas said:
1. The angular momentum of a particle under the influence of a central force is
a) Infinite b) Negative c) ZERO d) Constant
reason: bcoz angular momentum is always act externally.
d) Constant
reason: Kepler's law

abrowaqas said:
2. Transverse component of the central force acting on a particle to keep it moving along a path is
a) Mv2r b)mv2/r c) ZERO d) constant
reason: bcoz there is no transverse component of velocity
b) mv2/r
reason: it's a transverse component of force, not of velocity

abrowaqas said:
7. Which type of ideal gas will have the largest value for Cp-Cv
a) MONOATOMIC b) diatomic c) polyatomic d) the value is same for all
reason: it was an educated guess.
d) the value is same for all
reason: Cp-Cv=R

abrowaqas said:
8. What would be the most likely value for Ct, the molar heat capacity at constant temperature
a) Zero b) zero<Ct< Cv c) CV<CT<CP d) Ct= infinite
reason: here answer is C. it was a guess.
d) Ct=infinite
reason: Ct = (dU/dT) at constant T, since T is constant, dT is 0, making dU/dT infinite.
Actually, the result is undefined, because dU could be 0 as well, but "undefined" is not a choice.

abrowaqas said:
15. If the particle of liquid which pass through a certain point do not follow the same path, as that followed by the particles that passed the same point previously the liquid is said to have
a) STEADY b) Non steady flow c) turbulent flow d)None of these
b) Non steady flow
reason: from the question, the flow is not steady
 
thanks I like serena..

is that means all other are correct?
 
abrowaqas said:
thanks I like serena..

is that means all other are correct?

According to my 2 cents all the others are correct.
 
serena you said that the central force has mv2/r component..
but one of my friend told me that central force is always directing at the radial direction hence it has only radial component.. it has no transverse component.
what you say about it?
 
abrowaqas said:
serena you said that the central force has mv2/r component..
but one of my friend told me that central force is always directing at the radial direction hence it has only radial component.. it has no transverse component.
what you say about it?

Oops. I mixed up tangential and transverse.
Central force is indeed always radial and has no tangential component.
 

Similar threads

  • · Replies 18 ·
Replies
18
Views
3K
  • · Replies 1 ·
Replies
1
Views
2K
Replies
5
Views
3K
  • · Replies 3 ·
Replies
3
Views
806
  • · Replies 2 ·
Replies
2
Views
2K
  • · Replies 8 ·
Replies
8
Views
2K
  • · Replies 58 ·
2
Replies
58
Views
5K
  • · Replies 6 ·
Replies
6
Views
2K
  • · Replies 12 ·
Replies
12
Views
3K
  • · Replies 13 ·
Replies
13
Views
8K