Two temperature scales A and B are related by . At which temperature two scales have the same reading ?
− 42°
− 72°
+ 12°
− 40°
An ideal gas is compressed isothermally until its pressure is doubled and then allowed to expand adiabatically to regain its original volume (γ = 1.4 and 2-1.4 = 0.38). The ratio of the final to initial pressure is
0.76 : 1
1 : 1
0.66 : 1
0.86 : 1
Air inside a closed container is saturated with water vapour. The air pressure is p and the saturated vapour pressure of water is . If the mixture is compressed to one-half of its volume by maintammg temperature constant, the pressure becomes
1.56 x 105 J of heat is conducted through a 2 m2 wall of 12 cm thick in 1 h. Temperature difference between the two sides of the wall is 20° C. The thermal conductivity of the material of the wall is (in W m-1 K-1)
0.11
0.13
0.15
1.2
Five equal resistance, each of resistance R are connected as shown in figure below. A battery of V volt is connected between A and B. The current flowing in FC will be
C.
The effective figure can be given by
From the Wheatstone bridge balance, we get
Hence, no current flows through the central resistance C. Thus, the effective resistance is
equal to
Hence, Reff = R
Now, the current , hence the current through FC would be equal to
Two cells with the same emf E and different internal resistances r1 and r2 are connected in series to an external resistance R. The value of R so that the potential difference across the first cell be zero, is
r1 + r2
r1 − r2
Current through ABC and A' B'C' is I. What is the magnetic field at P ? BP = PB' = r (Here C' B' PBC are collinear)
Zero