List of top Physics Questions

For a solid rod, the Young's modulus of elasticity is $32 \times 10^{11} Nm ^{-2}$ and density is $8 \times 10^3 kg m ^{-3}$ The velocity of longitudinal wave in the rod will be

The amplitude of $15 \sin (1000 \pi t )$ is modulated by $10 \sin (4 \pi t )$ signal The amplitude modulated signal contains frequency (ies) of 
A $500\,Hz$ 
B $2\, Hz$ 
C $250\, Hz$ 
D $498\, Hz$ 
E $502\, Hz$ 
Choose the correct answer from the options given below:

A person driving car at a constant speed of 15 m/s is approaching a vertical wall. The person notices a change of 40 Hz in the frequency of his car’s horn upon reflection from the wall. The frequency of horn is ____ Hz.
A travelling wave is described by the equation $y(x, t)=[0.05 \sin (8 x-4 t)] m$ The velocity of the wave is : [all the quantities are in SI unit]
A train blowing a whistle of frequency $320 Hz$ approaches an observer standing on the platform at a speed of $66 m / s$ .The frequency observed by the observer will be ____ Hz,
(Given speed of sound $=330 ms ^{-}$ 1)
The distance between two consecutive points with phase difference of $60^{\circ}$ in a wave of frequency $500 \,Hz$ is $60\, m$ The velocity with which wave is traveling is ___$km / s$

Given below are two statements : 
Statement I : For transmitting a signal, size of antenna ( $f$ ) should be comparable to wavelength of signal (at least $l=\frac{\lambda}{4}$ in dimension)
Statement II : In amplitude modulation, amplitude of carrier wave remains constant (unchanged) 
In the light of the above statements, choose the most appropriate answer from the options given below,

The displacement equations of two interfering waves are given by
\(y_1=10 \sin \left(\omega t+\frac{\pi}{3}\right)\) cm ,
 \(y_2=5[\sin \omega t+\sqrt{3} \cos \omega t]\) cm respectively.
The amplitude of the resultant wave is ___ cm

A steel wire with mass per unit length $70 \times 10^{-3} kg\, m ^{-1}$ is under tension of $70 \,N$.
The speed of transverse waves in the wire will be:
In an experiment with sonometer when a mass of 180 g is attached to the string, it vibrates with fundamental frequency of 30 Hz. When a mass m is attached, the string vibrates with fundamental frequency of 50 Hz. The value of m is ______g.
If 917 Å be the lowest wavelength of Lyman series then the lowest wavelength of Balmer series will be _____ Å.
A carrier wave of amplitude 15 V modulated by a sinusoidal base band signal of amplitude 3 V. The ratio of maximum amplitude to minimum amplitude in an amplitude modulated wave is
A guitar string of length 90 cm vibrates with a fundamental frequency of 120 Hz. The length of the string producing a fundamental frequency of 180 Hz will be _______ cm.
A wire of density \(8 × 10^3\) \(kg/m^3\) is stretched between two clamps 0.5 m apart. The extension developed in the wire is \(3.2 × 10^{–4}\) m. If Y = \(8 × 10^{10}\) \(N/m^2\) , the fundamental frequency of vibration in the wire will be ________Hz.
The power radiated from a linear antenna of length \( l \) is proportional to: (Given, \( \lambda \) = Wavelength of wave):
A proton and an α-particle are accelerated from rest by 2V and 4V potentials, respectively. The ratio of their de-Broglie wavelength is
Given below are two statement : one is labelled as Assertion A and the other is labelled as Reason R.  
Assertion A : EM waves used for optical communication have longer wavelengths than that of microwave, employed in Radar technology.  
Reason R : Infrared EM waves are more energetic than microwaves, (used in Radar)  
In the light of given statements, choose the correct answer from the options given below:  
A beam of light consisting of two wavelengths 7000 Å and 5500 Å is used to obtain interference pattern in Young's double slit experiment. The distance between the slits is 2.5 mm and the distance between the plane of slits and the screen is 150 cm. The least distance from the central fringe, where the bright fringes due to both the wavelengths coincide, is n × 10-5 m. The value of n is_____.
A single slit of width a is illuminated by a monochromatic light of wavelength 600 nm. The value of 'a' for which first minimum appears at θ=30° on the screen will be :
A message signal of frequency 3kHz is used to modulate a carrier signal of frequency 1.5 MHz. The bandwidth of the amplitude modulated wave is 
The width of fringe is 2 mm on the screen in a double slits experiment for the light of wavelength of 400 nm. The width of the fringe for the light of wavelength 600 nm will be:
Given below are two statements: one is labelled as Assertion A and the other is labelled as Reason R  
Assertion A: The phase difference of two light waves change if they travel through different media having same thickness, but different indices of refraction.  
Reason R: The wavelengths of waves are different in different media.  
In the light of the above statements, choose the most appropriate answer from the options given below 
The difference between threshold wavelengths for two metal surfaces A and B having work function \(Φ_A\)= 9 eV and \(Φ_B\) = 4.5 eV in nm is:
{Given, hc = 1242 eV nm}
Given below are two statement : one is labelled as Assertion A and the other is labelled as Reason R.  
Assertion A : EM waves used for optical communication have longer wavelengths than that of microwave, employed in Radar technology.  
Reason R : Infrared EM waves are more energetic than microwaves, (used in Radar)  
In the light of given statements, choose the correct answer from the options given below:  
The equation of wave is given by \( Y = 10^2 \sin 2 \pi \left( (60t - 0.5x + \frac{\pi}{4}) \right) \) where \( x \) and \( Y \) are in m and t in s. The speed of the wave is _____ km h\(^{-1}\).