# Thermodynamics (NEET (NTA)-National Eligibility cum Entrance Test (Medical) Physics): Questions 42 - 45 of 86

Access detailed explanations (illustrated with images and videos) to 2144 questions. Access all new questions we will add tracking exam-pattern and syllabus changes. Subscription can be renewed yearly absolutely FREE! View Sample Explanation or View Features.

Rs. 550.00 or

How to register?

## Question number: 42

» Thermodynamics » Thermal Equilibrium

Edit
MCQ▾

### Question

In the diagrams (i) to (iv) of variation of volume with changing pressure is shown. A gas is taken along the path ABCD. The change in internal energy of the gas will be

### Choices

Choice (4) Response

a.

Positive in cases (i), (ii) and (iii) but zero in case (rv)

b.

Negative in cases (i), (ii) and (iii) but zero in case (iv)

c.

Positive in all cases (i) to (iv)

d.

Zero in all cases

## Question number: 43

» Thermodynamics » Laws of Thermodynamics » First Law of Thermodynamics

Edit
MCQ▾

### Question

The specific heat of hydrogen gas at constant pressure is and at constant volume is . If one kilogram hydrogen gas is heated from 10°C to 20°C at constant pressure, the external work done on the gas to maintain it at constant pressure is

### Choices

Choice (4) Response

a.

10 3 Cal

b.

10 4 Cal

c.

10 5 Cal

d.

5 ⨯ 10 3 Cal

## Question number: 44

» Thermodynamics » Concept of Temperature

Edit
MCQ▾

### Question

A scientist says that the efficiency of his heat engine which operates at source temperature 120°C and sink temperature 27°C is 26%, then

### Choices

Choice (4) Response

a.

Data are incomplete

b.

It is possible but less probable

c.

It is impossible

d.

It is quite probable

## Question number: 45

» Thermodynamics » Concept of Temperature

Edit
MCQ▾

### Question

Efficiency of a Carnot engine is 50 % when temperature of outlet is 400 K. In order to increase efficiency up to 70 % keeping temperature of intake the same what will be temperature of outlet

### Choices

Choice (4) Response

a.

870 K

b.

460 K

c.

690 K

d.

240 K