A metro train starts from rest and in 5 s achieves 108 km/h. After that it moves with constant velocity and comes to rest after travelling 45 m with uniform retardation. If total distance travelled is 395 m, find total time of travelling.
12.2 s
15.3 s
9 s
17.2 s
A tuning fork A produces 4 beats/s with another tuning fork B of frequency 320 Hz. On filing one of the prongs of A, 4 beats/s are again heard when sounded with the same fork B. Then, the frequency of the fork A before filing is
328 Hz
316 Hz
324 Hz
320 Hz
If there were no gravity, which of the following will not be there for a fluid?
Viscosity
Surface tension
Pressure
Archimedes' upward thrust
In Young's double slit experiment with sodium vapour lamp of wavelength 589 nm and the slits 0.589 mm apart, the half angular width of the central maximum is
sin-1 (0.01)
sin-1 (0.0001)
sin-1 (0.001)
sin-1 (0.1)
In Carnot engine efficiency is 40% at hot reservoir temperature T. For efficiency 50%, what will be temperature of hot reservoir?
6 T
D.
The efficiency of a heat engine is defined as the ratio of work done to the heat supplied, ie,
=
⇒
where T2 is temperature of sink, and T1 is temperature of hot reservoir.
∴
⇒
⇒
Again,
⇒
⇒
∴
⇒
Which one of the following statements is true?
Both light and sound waves in air are transverse
The sound waves in air are longitudinal while the light waves are transverse
Both light and sound waves in air are longitudinal
Both light and sound waves can travel in vacuum
A closed organ pipe of length 20 cm is sounded with tuning fork in resonance. What is frequency of tuning fork? (v = 332 m/s)
300 Hz
350 Hz
375 Hz
415 Hz
The temperature of the sun can be found out by using
Wien's displacement law
Kepler's law of motion
Stefan's Boltzmann law
Planck's law
Pressure of an ideal gas is increased by keeping temperature constant. What is effect on kinetic energy of molecules?
Increase
Decrease
No change
Cannot be determined
A transverse wave is expressed as, For what value of λ, maximum particle velocity equals to 4 times the wave velocity?