Physics Academy : +2 Science

The modulation index in amplitude modulation is:
(a) Always zero
(b) Between 0 and 1
(c) Between 1 and ∞
(d) None of these

Answer
Answer: (c) Between 1 and ∞

A microphone converts:
(a) sound signals into electrical signals
(b) electrical signals into sound signals
(c) both (a) and (b)
(d) Neither (a) nor (b)

Answer
Answer: (a) sound signals into electrical signals

Broadcasting antenna are generally:
(a) Ommi directional type
(b) Vertical type
(c) Horizontal type
(d) None

Answer
Answer: (b) Vertical type

The audio frequencies range from:
(a) 20 Hz to 20.000 kHz
(b) 20 Hz to 20 kHz
(c) 20 kHz to 20.000 kHz
(d) None of these

Answer
Answer: (b) 20 Hz to 20 kHz

The term used “to collect the information about an object and a place without physical contact” is called :
(a) modulation
(b) communication
(c) amplification
(d) remote sensing

ANS: Remote sensing.

Question 1.
Who undertook the first space walk and in which year?
(a) Leonov 1965
(b) Neil Armstrong, 1969
(c) Rakesh Sharma. 1998
(d) None of these

Answer
Answer: (a) Leonov 1965

Which of the following remains constant if a body travels with constant acceleration?

Time
Velocity
Displacement
None of the above
Answer: (d) None of the above

What can be said about the displacement of the body if it covers a distance of zero?

It is zero
It cannot be zero
It may or may not be zero
It is negative
Answer: (a) It is zero

Below is the distance-time curve traced by the particle. What is the maximum instantaneous velocity of the particle around the point
(a) D

(b) B

(c) A

(d) C

Answer: (d) C

What does the area under acceleration-time graph represent for any given time interval

(a) Final velocity

(b) Distance travelled

(c) Change in the velocity in that time interval

(d) Displacement of the particle

Answer: (c) Change in the velocity in that time interval