Related InterviewSolutions

• Two rods A and B of different materials are welded together as shown in figure. Their thermal conductivities are `K_(1)` and `K_(2)`. The thermal conductivity of the composite rod will be A. `(3(K_(1) + K_(2)))/(2)`B. `K_(1) + K_(2)`C. `2 (K_(1) + K_(2))`D. `(K_(1) + k_(2))/(2)`
• A disc and a solid sphere of same radius but different masses roll off on two inclined planes of the same altitude and length. Which one of the two objects gets to the bottom of the plane first ?A. DiskB. SphereC. Both reach at same timeD. Depends on their masses
• In an electromagnetic wave in free space the root mean square value of the electric field is `E_(rms)=6 V//m`. The peak value of the magnetic field isA. `2.83xx10^(-8) T`B. `0.70xx10^(-8) T`C. `4.23xx10^(-8) T`D. `1.41xx10^(-8) T`
• A pendulum is hung the roof of a sufficiently high huilding and is moving freely to and fro like a simple harmonic oscillator .The acceleration of the bob of the pendulum is `20m//s^(2)` at a distance of `5m` from the meanposition .The time period of oscillation isA. `2 s`B. `1 s`C. `pi s`D. `2 pi s`
• A small sphere falls from rest in a viscous liquid. Due to friction, heat is produced. Find the relation between the rate of production of heat and the radius of the sphere at terminal velocity.A. `r^(5)`B. `r^(4)`C. `r^(2)`D. `r^(3)`
• A `npn` transistor is connected in common emitter configuration in a given amplifier. A load resistance of `800 Omega`is connected in the collector circuit and the voltage drop across `0.96` and the input resistance of the circuit is `192 Omega`, the voltage gain and the power gain of the amplifier will respectively be :A. `4,3.84`B. `3.69,3.84`C. `4,4`D. `4,3.69`
• In a common emitter transistor amplifier the audio signal voltage across the collector is `3 V`. The resistance of collector is `3 kOmega`. If current gain is `100` and the base resistance is `2 kOmega`, the voltage and power gain of the amlifier is :A. `15` and `200`B. `150` and `15000`C. `20` and `2000`D. `200` and `1000`
• When a certain metallic surface is illuminated with monochromatic light of wavelength `lamda`, the stopping potential for photoelectric current is `3V_0` and when the same surface is illuminated with light of wavelength `2lamda`, the stopping potential is `V_0`. The threshold wavelength of this surface for photoelectrice effect isA. `4 lambda`B. `(lambda)/4`C. `(lambda)/6`D. `6 lambda`
• The de - Broglie wavelength of a neutron in thermal equilibrium with heavy water at a temperature `T ("kelvin")` and mass `m`, isA. `h/(sqrt(3mkT))`B. `(2h)/(sqrt(3mkT))`C. `(2h)/(sqrt(mkT))`D. `h/(sqrt(mkT))`
• A mass `m` moves in a circles on a smooth horizontal plane with velocity `v_(0)` at a radius `R_(0)`. The mass is atteched to string which passes through a smooth hole in the plane as shown. The tension in string is increased gradually and finally `m` moves in a cricle of radius `(R_(0))/(2)`. the final value of the kinetic energy is A. `(1)/(4) mv_(0^(2)`B. `2 mv_(0)^(2)`C. `(1)/(2) mv_(0^(2)`D. `m_(0)^(2)`