Q. 205.0( 1 Vote )
Give examples where effect of force is increased and decreased? Explain how.
Effect force is decreased in the foundation of buildings and dams. In vehicles, additional tyres are provided to carry heavy loads. The effect of force is decreased by increasing the area.
Rate this question :
Which of the following frequency of sound can be generated by a vibrating simple pendulum as well as by the vibrating vocal cords of a rhinoceros?
A. 5 kHz B. 25 Hz
C. 10 Hz D. 15,000 HzLakhmir Singh & Manjit Kaur - Physics
Name five appliances or machines which use an electric motor.Lakhmir Singh & Manjit Kaur - Physics
Illustrate the law of conservation of energy by discussing the energy changes which occur when we draw a pendulum bob to one side and allow it to oscillate. Why does the bob eventually come to rest?NCERT - Science
A sonar station picks up a return signal after 3 seconds. How far away is the object? (Speed of sound in water = 1440 m/s).Lakhmir Singh & Manjit Kaur - Physics
Name the devices or machines which convert:
(a) Mechanical energy into electrical energy.
(b) Chemical energy into electrical energy.
(c) Electrical energy into heat energy.
(d) Electrical energy into light energy.Lakhmir Singh & Manjit Kaur - Physics
The frequencies of four sound waves are given below. Which of these sound waves can be used to measure the depth of sea by the echo method?
A. 15,000 Hz B. 10 kHz
C. 50 kHz D. 10,000 HzLakhmir Singh & Manjit Kaur - Physics
Write the energy transformations which take place in an electric bulb (or electric lamp).Lakhmir Singh & Manjit Kaur - Physics
The speed of highly penetrating ultrasonic waves is:
A. lower than those of audible sound waves
B. higher than those of audible sound waves
C. much higher than those of audible sound waves
D. same as those of audible sound wavesLakhmir Singh & Manjit Kaur - Physics
Five electric fans of 120 watts each are used for 4 hours. Calculate the electrical energy consumed in kilowatt hours.Lakhmir Singh & Manjit Kaur - Physics
A man weighing 500 N carried a load of 100 N up a fighter of stairs 4 m high in 5 seconds. What is the power?Lakhmir Singh & Manjit Kaur - Physics