Two moles of exygen is mixed with eight moles of helium. The effective specific heat of the mixture at constant volume is
1.3 R
1.4 R
1.7 R
1.9 R
In damped oscillations, the amplitude of oscillations is reduced to one-third of its initial value a0 at the end of 100 oscillations. When the oscillator completes 200 oscillations, its amplitude must be
A particle executes simple harmonic motion with a time period of 16 s. At time t = 2 s, the particle crosses the mean position while at t = 4s, its velocity is 4 ms-1. The amplitude of motion in metre is
For a simple pendulum, the graph between T2 L and is
a straight line passing through the origin
parabola
circle
ellipse
Charges + 2q, + q and + q are placed at the comers A, B and C of an equilateral triangle ABC. If E is the electric field at the circumcentre 0 of the triangle, due to the charge + q, then the magnitude and direction of the resultant electric field at O is
E along AO
2E along AO
E along BO
E along CO
N identical drops of mercury are charged sumultaneously to 10 V. When combined to form one large drop, the potential is found to be 40 V, the value of N is
4
6
8
10
The electrostatic potential energy between proton and electron separated by a distance 1 is
13.6 V
27.2 eV
14.4 eV
1.44 eV
C.
14.4 eV
The plates of a parallel plate capacitor with air as medium are separated by a distance of 8 mm. A medium of dielectric constant 2 and thickness 4 mm having the same area is introduced between the plates. For the capacitance to remain the same, the distance between the plates is
8 mm
6 mm
10 mm
12 mm
The resistance of a wire at room temperature 30˜C is found to be 10 Ω. Now to increase the resistance by 10%, the temperature of the wire must be [The temperature coefficient of resistance of the material of the wire is 0.002/°C]
36°C
83°C
63°C
33°C