1
NEET 2018
MCQ (Single Correct Answer)
+4
-1
Change Language
A sample of 0.1 g of water at 100°C and normal pressure (1.013 × 105 N m–2) requires 54 cal of heat energy to convert to steam at 100°C. If the volume of the steam produced is 167.1 cc, the change in internal energy of the sample, is
A
104.3 J
B
208.7 J
C
42.2 J
D
84.5 J
2
NEET 2018
MCQ (Single Correct Answer)
+4
-1
Change Language
A thin diamagnetic rod is placed vertically between the poles of an electromagnet. When the current in the electromagnet is switched on, then the diamagnetic rod is pushed up, out of the horizontal magnetic field. Hence the rod gains gravitational potential energy. The work required to do this comes from
A
The current source
B
The magnetic field
C
The lattice structure of the material of the rod
D
The induced electric field due to the changing magnetic field
3
NEET 2018
MCQ (Single Correct Answer)
+4
-1
Change Language
The power radiated by a black body is P and it radiates maximum energy at wavelength, $$\lambda $$0 . If the temperature of the black body is now changed so that it radiates maximum energy at wavelength $${3 \over 4}{\lambda _0}$$, the power radiated by it becomes nP. The value of n is
A
$${3 \over 4}$$
B
$${4 \over 3}$$
C
$${{256} \over {81}}$$
D
$${{81} \over {256}}$$
4
NEET 2018
MCQ (Single Correct Answer)
+4
-1
Change Language
A solid sphere is rotating freely about its symmetry axis in free space. The radius of the sphere is increased keeping its mass same. Which of the following physical quantities would remain constant for the sphere?
A
Angular velocity
B
Moment of inertia
C
Rotational kinetic energy
D
Angular momentum