What is the full form of RADAR?
[7] Sound
Chapter: [7] Sound
Concept: undefined >> undefined
What is the difference between echo and reverberation?
[7] Sound
Chapter: [7] Sound
Concept: undefined >> undefined
What are the conditions necessary for the formation of echo?
[7] Sound
Chapter: [7] Sound
Concept: undefined >> undefined
Give a simple experiment to demonstrate the reflection of sound waves.
[7] Sound
Chapter: [7] Sound
Concept: undefined >> undefined
How will you find the velocity of sound waves?
[7] Sound
Chapter: [7] Sound
Concept: undefined >> undefined
Explain how the principle of echo is used by
The bat during its flight at
[7] Sound
Chapter: [7] Sound
Concept: undefined >> undefined
Explain how the principle of echo is used by
The dolphin to locate small fish as its prey
[7] Sound
Chapter: [7] Sound
Concept: undefined >> undefined
Name the waves which are used in sonar to find the depth of sea.
[7] Sound
Chapter: [7] Sound
Concept: undefined >> undefined
What do you mean by wave motion?
[7] Sound
Chapter: [7] Sound
Concept: undefined >> undefined
What is meant by echo? What are the conditions necessary for its formation?
[7] Sound
Chapter: [7] Sound
Concept: undefined >> undefined
Why do echoes produced in an empty auditorium usually decrease when it is full of audience?
[7] Sound
Chapter: [7] Sound
Concept: undefined >> undefined
Explain how is the principle of echo used by
(a) The bat during its flight at night,
(b) The dolphin to locate small fish as its prey.
[7] Sound
Chapter: [7] Sound
Concept: undefined >> undefined
How much work is done when 5 C charge moves across a p.d. of 1 V?
[8] Current Electricity
Chapter: [8] Current Electricity
Concept: undefined >> undefined
The device used for measuring potential difference is
[8] Current Electricity
Chapter: [8] Current Electricity
Concept: undefined >> undefined
How will you maintain a potential difference between the ends of a conductor?
[8] Current Electricity
Chapter: [8] Current Electricity
Concept: undefined >> undefined
A heater is rated at 1200 W when the electric current is 5 A. Calculate the resistance and the potential difference.
[8] Current Electricity
Chapter: [8] Current Electricity
Concept: undefined >> undefined
A current of 0.2 A flows through a wire whose ends are at a potential difference of 15 V. Calculate:
(i) The resistance of the wire, and
(ii) The heat energy produced in 1 minute.
[8] Current Electricity
Chapter: [8] Current Electricity
Concept: undefined >> undefined
Define the following:
Potential difference
[8] Current Electricity
Chapter: [8] Current Electricity
Concept: undefined >> undefined
What is the combined resistance of each of the networks between A and B shown in fig. ?

[8] Current Electricity
Chapter: [8] Current Electricity
Concept: undefined >> undefined
The voltage across a 3Ω resistance is 6 V. How large is the current? What is
the resistance of a filament lamp when a voltage of 3 V across it causes a
current of 0.5 A?
[8] Current Electricity
Chapter: [8] Current Electricity
Concept: undefined >> undefined