4 Marks Question - Physics STD 11 Science Questions - Vidyadip

Questions

4 Marks Question

Take a timed test

2 questions · self-marked practice — reveal the answer and mark yourself.

Question 14 Marks

The number of independent ways by which a dynamic system can move, without violating any constraint imposed on it, is called the number of degrees of freedom. According to the law of equipartition of energy, for any dynamic system in thermal equilibrium, the total energy for the system is equally divided among the degree of freedom.

1. If gas has n degree of freedom, the ratio of specific heat is:
(a) $-2 n$ (b) $2 n$ (c) $1+2 / n$ (d) $1-2 / n$
2. The kinetic energy, due to translational motion, of most of the molecules of an ideal gas at absolute temperature T, is:
(a) $kT ^3$ (b) $kT ^2$ (c) kT (d) $k / T$
3. The mean free path is the:
(a) length of the container that contains the gas
(b) mean of the square of the average distance between two successive collisions
(c) the average distance covered by a molecule between two successive collisions
(d) height of the container that contains the gas
4. The law of equipartition of energy is applicable to the system whose constituents are:
(a) in non random motion
(b) in random motion
(c) in orderly motion
(d) in rest
OR
Thermochemical calorie is equal to
(a) 41.48 joule (b) 4.148 joule (c) 4148 joule (d) 414.8 joule

Answer

1. (c) $1+2 / n$
Explanation: $1+2 / n$
2. (c) kT
Explanation: kT
3. (c) the average distance covered by a molecule between two successive collisions
Explanation: the average distance covered by a molecule between two successive collisions
4. (b) in random motion
Explanation: in random motion
OR
(b) 4.148 joule
Explanation: 4.148 joule

View full question & answer→

Question 24 Marks

There are many types of spring. Important among these are helical and spiral springs as shown in the figure.

Usually, we assume that the springs are massless. Therefore, work done is stored in the spring in the form of the elastic potential energy of the spring. Thus, the potential energy of a spring is the energy associated with the state of compression or expansion of an elastic spring.

1. The potential energy of a spring increases in which of the following cases?
(a) If work is done against conservative force
(b) If work is done by non-conservative force force
(c) If work is done by conservative force
(d) If work is done against nonconservative force
2. The potential energy, i.e. $U(x)$ can be assumed zero when
(a) gravitational force is constant
(b) $x=0$
(c) infinite distance from the gravitational source
(d) All of these
3. The ratio of spring constants of two springs is $2: 3$. What is the ratio of their potential energy, if they are stretched by the same force?
(a) $3: 2$ (b) $9: 4$ (c) $2: 3$ (d) $4: 9$
OR
The potential energy of a spring when stretched through a distance x is 10 J . What is the amount of work done on the same spring to stretch it through an additional distance $x$ ?
(a) 40 J (b) 10 J (c) 30 J (d) 20 J
4. The potential energy of a spring increases by 15 J when stretched by 3 cm . If it is stretched by 4 cm , the increase in potential energy is
(a) 36 J (b) 30 J (c) 27 J (d) 33 J

Answer

1. (a) If work is done against conservative force
Explanation: If work is done against conservative force
2. (d) All of these
Explanation: All of these
3. (a) $3: 2$
Explanation: $3: 2$
OR
(c) 30 J
Explanation: 30 J
4. (c) 27 J
Explanation: 27 J

View full question & answer→

Generate Paper Free All Model Paper 1 topics

4 Marks Question - Physics STD 11 Science Questions - Vidyadip