List of top Physics Questions

Which of the following is a transducer ?
(A) Loudspeaker
(B) Amplifier
(C) Rectifier
(D) Microphone
Choose the correct answer from the options given below :
A semiconductor has an electron concentration of 8 x 1013 m-3 and hole concentration of 2 × 103 m-3. The semiconductor behaves as:
What is the wavelength of light for the least energetic photon emitted in the Lyman series of the hydrogen atom spectrum lines?
(Take h=6.63×10-34Js; c=3×108 ms-1; e=1.6×10-19C)
A \(ẞ\)-particle is moving perpendicular to the uniform electric field created by a potential difference of \(6 × 10^3\) V across parallel metal plates separated by a vertical distance of 6 cm. What is the acceleration of the beta particle between the plates? (Mass of electron = \(9.1 × 10^{-31}\)kg) 
A vertical electric field of magnitude 4.9×105 NC-1 just prevents a water droplet of mass 0.1 g from falling. What is the charge on the droplet? Take acceleration due to gravity 9.8 ms-2.
Match List I with List II
List IList II
(A) Zener Diode(II) Voltage Regulator
(B) LED(III) Remote Control
(C) Rectifier(IV) AC to DC
(D) Photo diode(I) Detect optical signal
C.V. Raman got Nobel Prize in 1930 for his discovery of:
The type of wavefront that emerges from a distant light source is:
A spherical conducting shell of inner radius r₁ and outer radius r₂ has a charge Q. A charge q is placed at the centre of the shell. The surface charge density on outer surface of the shell is:
Match List I with List II
LIST I LIST II
A.ConductanceI.[ML3 T-3A-2]
B.Current densityII.[M-1L-3 T3 A2]
C.Specific resistanceIII.[M0L-2 T0A¹]
D.Electrical conductivitiesIV.[M-1L-2 T3 A2]
Choose the correct answer from the options given below:
After 4 hours,\(\frac{1}{16}\) of the initial amount of a certain radioactive isotype remains undecayed. What is the half life of the isotope?
An alternating voltage V = 140 sin 100 πt is connected across a pure resistor of resistance 40 Ω. What is the rms current through the resistor? (Take √2 = 1.4)
A conducting sphere of radius R is given a charge Q. What is the electric field and the electric potential at the centre of the sphere?
SI unit of temperature is ________.
Energy band gap is maximum in:
Kirchhoff's Second Law is based on law of conservation of:
When 100 V dc is applied across a solenoid, a current of 1 A flows in it. When 100 V ac is applied across the same solenoid the current drops to 0.5 A. If the frequency of the ac source is 50 Hz, the impedance and inductance of the solenoid are:
The truth table for one of the following logic gates is given. Identify the logic gate
InputOutput
ABY
001
011
101
110
For a glass prism (μ= √3), the angle of minimum deviation is equal to the angle of prism. What is the angle of prism?
The statement that is NOT true about induced emf is:
Choose the correct answer from the following:
If three charged particles are collinear and are in equilibrium, then:
Which of the following statements is NOT correct:
If x is inversely proportional to y and y is directly proportional to z, then xz is :
A slit of width \(e\) is illuminated by light of wavelength \(\lambda\). What should be the value of \(e\) to obtain the first maximum at an angle of diffraction \(\frac{\pi}{3}\)?
Which of the following statements are correct?
(A) The resistivity of a semiconductor decreases with increasing temperature.
(B) The potentiometer is unaffected by the internal resistance of the source.
(C) In ionic crystals and electrolytic liquids electrons carry the electric current.
(D) Ohm's law fails if V depends on I non-linearly.
(E) Kirchhoff's rules are used for analysis of electric circuits.
Choose the correct answer from the options given below: