Spheres of iron and lead having same mass are completely immersed in water. Density of lead is more than that of iron. Apparent loss of weight is w1 for iron sphere and w2 for lead sphere, Then is
> 1
= 1
become 0 and 1
= 0
A hot body is allowed to cool. The surrounding temperature is constant at 30°C. The takes time t1 to cool from 70°C to 68°C and time t2 to cool from 60°C to 59.5°C. Then
t2 = t1
t2 = 2t1
t2 = 4t1
A particle executes SHM with amplitude 0.2 m and time period 24 s. The time required it to move from the mean position to a point 0.1 m from the mean position is
12 s
2 s
8 s
3 s
The circular motion of a particle with constant speed is
neither periodic nor SHM
periodic but not SHM
SHM but not periodic
periodic and also SHM
A, B and C are the three identical conductors but made from different materials. They are kept in contact as shown
Their thermal conductivities are K, 2K and . The free end of A is at 100°C and the free end of C is at 0°C. During steady state, the temperature of the junction of A and B is nearly
37°C
71°C
29°C
63°C
One mole of an ideal gas is taken from A to B, from B to C and then C and A and then the variation of its volume with temperature for that change is as shown. Its pressure is p0, volume is V0, then the internal energy is
at A and B are equal
at A is more than at B
at C is less than at B
at B is more than at A
A.
at A and B are equal
Process A➔ B is isothermal, hence internal energies at A and B are equal.
Which ofthe following is incorrect?
'Diffraction' helps us to distinguish between sound wave and light wave.
If the wave is longitudinal, it must be a mechanical wave.
If the wave is mechanical, it may or may not be a transverse wave
Mechanical waves cannot propagate in vacuum.
In the uniform electric field of E = 1 x 104 NC-1, an electron is accelerated from rest. The velocity of the electron when it has travelled a distance of 2 × 10-2 m is nearly
8.5 × 106 ms-1
1.6 × 106 ms-1
0.85 × 106 ms-1
0.425 × 106 ms-1
In this diagram, the PD between A and B is 60 V. The PD across 6 µF capacitor is
4 V
10 V
5 V
20 V
In this circuit, when certain current flows, the heat produced in 5 Ω is 4.05 J in a time t. The heat produced in 2 Ω coil in the same time interval is
2.02
5.76
1.44
2.88