A cylinder of radius $R$ made of a material of thermal conductivity $k_1$ is surrounded by a cylindrical shell of inner radius $R$ and outer radius $2 R$ made of a material of thermal conductivity $k_2$. The two ends of a combined system are maintained at two different temperature. There is no loss of heat across the cylindrical surface and the system is in steady state. The effective thermal conductivity of the system is
$k_1+k_2$
$\frac{k_1+3 k_2}{4}$
$\frac{k_1 k_2}{k_1+k_2}$
$\frac{3 k_1+k_2}{4}$
The mass of proton is 1.0073 u and that of neutron is $1.0087 \mathrm{u}(\mathrm{u}=$ atomic mass unit). The binding energy of ${ }_2 \mathrm{He}^4$ is
28.4 MeV
0.061 u
0.0305 J
0.0305 erg
In a certain process, 400 cal of heat is supplied to a system and at the same time 105 J of mechanical work was done on the system. The increase in its internal energy is
20 cal
303 cal
404 cal
425 cal
A standing wave $y=A \sin \left(\frac{20}{3} \pi x\right) \cos (1000 \pi t)$ is maintained in a taught string, where $y$ and $x$ are in metres. The distance between two successive points oscillating with the amplitude $\frac{A}{2}$ across a node is
2.5 cm
25 cm
5 cm
10 cm
BITSAT Papers
All year-wise previous year question papers