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
C.
In damped oscillation, amplitude goes on decaying exponentially
a = a0e-bt
where b = damping coefficient.
Initially,
where T is time of one oscillation.
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
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