List of top Physics Questions

The forbidden energy gaps in conductors, semiconductors and insulators are (Eg)c, (Eg)s and (Eg)1 respectively. What is the relation among them ?
Match List I with List II

List-I

List-II

(A)To slow down fast moving neutrons(I)Thermal neutrons
(B)A neutron or a proton(II)Fission
(C)Slow neutrons(III)Moderator
(D)Neutron induced nuclear reaction(IV)Nucleon

Choose the correct answer from the options given below:
Which of the following statements are correct for a transistor action ?
(A) The input resistance depends upon the current IC in the transistor
(B) Collector currents is equal to the sum of base current and emitter current
(C) The emitter junction is forward biased
(D) The collector junction is reverse biased
(E) Both the emitter junction as well as the collector junction are forward biased
Choose the correct answer from the options given below:
Which of the following graph correctly shows the relation between photoelectric current (I) and wavelength (λ) of incident radiation
Mobility of electrons
Ferromagnetic material core used for transformer must have
Identify the logic operation carried out by the following circuit.
logic operation carried out
Match List I with List II
List IList II
(A) Rn22286 → Po21884(III) α particle
(B) Bi21483 → Po21484(I) β− particle
(C) Th23490 → U23492(I) β− particle
(D) Na2211 → Na2210(II) β+ particle
The graph showing correct variation of photo current with intensity of incident light:
10 resistors, each of resistance R are connected in series to a battery of emf E and negligible internal resistance. Then those are connected in parallel to the same battery, the current is increased n times. The value of n is:
Brief exposure to the sound of minimum can damage ear drums of humans.
Match LIST I with LIST II

LIST I
Device

LIST II 
Purpose
AMicrophoneIUsed in vehicles to measure distance
BAudiometerIIFor measuring the force and velocity of
wind
C OdometerIIIConverts sound waves to electrical vibrations
DAnemometer IVMeasures intensity of sound
Choose the most appropriate answer from the options given below:
Two thin lenses of power +3D and -1D are held in contact with each other. Focal length of the combination would be:
A transmitting antenna at the top of a tower has a height 18 m and the height of the receiving antenna is 32 m. What is the maximum distance between them for satisfactory communication in line-of-sight mode? Given radius of earth is 6.4 × 106 m
If a copper wire carries a direct current, the magnetic field associated with the current would be:
Six equal resistances each of 4 Ω are connected to form a network as shows in figure. The resistance between A and B would be:
Resistance
Who among the following in Ancient India made some prominent discoveries in Physics?
Which one of the following cannot be polarised?
What is the de Broglie wavelength associated with an electron accelerated through a potential difference of 64 volts?

An infinitely-long conductor has a current of 14A flowing as shown in the figure. Find the magnetic field at center C.

If half life for a radioactive decay reaction is T. Find the time after which \(\frac{7}{8}th\) of initial mass decays
When electric field is applied to the electrons in a conductor it starts
Wire A and B have their Young’s moduli in the ratio 1:3, area of cross section in the ratio of 1:2 and lengths in ratio of 3:4. If same force is applied on the two wires to elongate then ratio of elongation is equal to
A particle of mass m moving with a velocity v collides with a particle of mass 2m at rest and sticks to it. Velocity of the combined mass equal to? 
Electric potential at a point \( P \) due to a point charge of \( 5 \times 10^{-9} \, \text{C} \) is \( 50 \, \text{V} \). The distance of \( P \) from the point charge is: