# NEET Physics: Questions 1511 - 1517 of 2142

Get 1 year subscription: Access detailed explanations (illustrated with images and videos) to 2142 questions. Access all new questions we will add tracking exam-pattern and syllabus changes. View Sample Explanation or View Features.

Rs. 550.00 or

## Question number: 1511

MCQ▾

### Question

The efficiency of Carnot’s engine operating between reservoirs, maintained at temperatures 27 degree Celsius and -113 degree Celsius

### Choices

Choice (4) Response

a.

0.4%

b.

50%

c.

0.75%

d.

46%

## Question number: 1512

MCQ▾

### Question

The ratio of the radii of the nuclei 13 Al 27 and 52 Te 125 is approximately -

### Choices

Choice (4) Response

a.

6: 10

b.

14: 73

c.

40: 177

d.

13: 52

## Question number: 1513

» Thermodynamics » Laws of Thermodynamics » First Law of Thermodynamics

MCQ▾

### Question

The first law of thermodynamics is concerned with the conservation of

### Choices

Choice (4) Response

a.

Mass

b.

Energy

c.

Temperature

d.

Momentum

## Question number: 1514

MCQ▾

### Question

The energy released per fission of U 235 is about 200 MeV. A reactor using U 235 as fuel is producing 1000 kilowatt power. The number of U 235 nuclei undergoing fission per sec is, approximately-

### Choices

Choice (4) Response

a.

3 × l0 16

b.

2 × 10 8

c.

10 6

d.

931

## Passage

Read the passage given below and answer the questions that follow:

In a living organism, the quantity of C 14 is the same as in the atmosphere. But in organisms which are dead, no exchange takes place with the atmosphere and by measuring the decay rate of 14 C in the old bones or wood, the time taken for the activity to reduce to this level can be calculated. This gives the age of the wood or bone.

Given: T 1/2 for 14 C is 5370 years and the ratio of is 1.3 ⨯ 10 -12.

## Question number: 1515 (1 of 3 Based on Passage) Show Passage

MCQ▾

### Question

If in an old sample of wood of 10g the decay rate is 30 decays per minute, the age of the wood is

### Choices

Choice (4) Response

a.

15300 years

b.

13310 years

c.

1000 years

d.

50 years

## Question number: 1516 (2 of 3 Based on Passage) Show Passage

MCQ▾

### Question

The decay rate in another piece is found to be 0.30 Bq per gm then we can conclude,

### Choices

Choice (4) Response

a.

The observed decay is not that of 14 C alone

b.

There is a statistical error

c.

he sample is very recent

d.

All a. , b. and c. are correct

## Question number: 1517 (3 of 3 Based on Passage) Show Passage

MCQ▾

### Question

The decay rate of 14 C in l gm of carbon in a living organism is,

### Choices

Choice (4) Response

a.

25 Bq

b.

0.25 Bq

c.

2.5 Bq

d.

5 Bq

f Page