To determine the correct statements, we need to analyze each given statement:
(A) Weight of a substance is the amount of matter present in it.
This is incorrect. The weight of a substance refers to the force of gravity acting on its mass. The mass, on the other hand, is the amount of matter in a substance.
(B) Mass is the force exerted by gravity on an object.
This is incorrect. The force exerted by gravity on an object is referred to as its weight, not its mass.
(C) Volume is the amount of space occupied by a substance.
This statement is true. Volume is indeed the measure of the amount of three-dimensional space an object occupies.
(D) Temperatures below 0°C are possible in Celsius scale, but in Kelvin scale negative temperature is not possible.
This statement is true. In the Kelvin scale, 0 K is the absolute zero point, and temperatures cannot go below this value. In the Celsius scale, temperatures can go below 0°C.
(E) Precision refers to the closeness of various measurements for the same quantity.
This statement is true. Precision is defined as the degree to which repeated measurements under unchanged conditions show the same results.
After analyzing the statements, the correct option is:
(C), (D) and (E) Only
The ratio of the power of a light source \( S_1 \) to that of the light source \( S_2 \) is 2. \( S_1 \) is emitting \( 2 \times 10^{15} \) photons per second at 600 nm. If the wavelength of the source \( S_2 \) is 300 nm, then the number of photons per second emitted by \( S_2 \) is ________________ \( \times 10^{14} \).
Match List - I with List - II:
List - I:
(A) Electric field inside (distance \( r > 0 \) from center) of a uniformly charged spherical shell with surface charge density \( \sigma \), and radius \( R \).
(B) Electric field at distance \( r > 0 \) from a uniformly charged infinite plane sheet with surface charge density \( \sigma \).
(C) Electric field outside (distance \( r > 0 \) from center) of a uniformly charged spherical shell with surface charge density \( \sigma \), and radius \( R \).
(D) Electric field between two oppositely charged infinite plane parallel sheets with uniform surface charge density \( \sigma \).
List - II:
(I) \( \frac{\sigma}{\epsilon_0} \)
(II) \( \frac{\sigma}{2\epsilon_0} \)
(III) 0
(IV) \( \frac{\sigma}{\epsilon_0 r^2} \) Choose the correct answer from the options given below:
Consider the following statements:
A. Surface tension arises due to extra energy of the molecules at the interior as compared to the molecules at the surface of a liquid.
B. As the temperature of liquid rises, the coefficient of viscosity increases.
C. As the temperature of gas increases, the coefficient of viscosity increases.
D. The onset of turbulence is determined by Reynolds number.
E. In a steady flow, two streamlines never intersect.
Choose the correct answer from the options given below: