# Communication System-Need for Modulation (NEET Physics): Questions 1 - 3 of 6

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: 1

» Communication System » Need for Modulation

MCQ▾

### Question

The acceleration due to gravity at a place can be determined with the help of a simple pendulum. For this purpose effective length of the pendulum is considered. If ′ be the length of the string and ‘d’ the diameter of the bob then the effective length is equal to

### Choices

Choice (4) Response

a.

l + d

b.

c.

l-d

d.

## Question number: 2

» Communication System » Need for Modulation

MCQ▾

### Question

Students I, II and III perform an experiment for measuring the acceleration due to gravity (g) using a simple pendulum. They use different lengths of the pendulum and/or record time for different number of oscillations. The observations are shown in the table. Least count for length = 0.1 cm

 Student Length of the pendulum (cm) No. of oscillations (n) Total time for (n) oscillations (s) Time Period (s) I 64.0 8 128.0 16.0 II 64.0 4 64.0 16.0 III 20.0 4 36.0 9.0

If E I, E II and E III are the percentage errors in g, i. e. , ( for students, I, II and III, respectively, then

### Choices

Choice (4) Response

a.

E I = 0

b.

E I = E II

c.

E I is minimum

d.

E II is maximum

## Question number: 3

» Communication System » Need for Modulation

MCQ▾

### Question

An oscillator is producing FM waves of frequency 4 kHz and modulating index is 8. Thus calculate the variation.

### Choices

Choice (4) Response

a.

5.0

b.

0.20

c.

0.67

d.

1.5

f Page