To solve the given problem, let's analyze each statement independently:
Statement I: In a vernier calipers, one vernier scale division is always smaller than one main scale division.
The vernier caliper is a precision instrument used to measure lengths. It consists of a main scale and a sliding vernier scale. Typically, each vernier scale division is slightly smaller than a main scale division. This is a fundamental design principle of a vernier caliper, enabling it to measure smaller increments accurately by using the difference between these scales. Thus, Statement I is true.
Statement II: The vernier constant is given by one main scale division multiplied by the number of vernier scale divisions.
The vernier constant (also called the least count) is defined as the difference between one main scale division and one vernier scale division. Mathematically, it is given by:
Vernier Constant = Length of one main scale division - Length of one vernier scale division.
The statement suggests it is calculated by multiplying a main scale division by the number of vernier scale divisions, which is incorrect. The vernier constant is determined by the small difference between these divisions, not multiplication. Therefore, Statement II is false.
Based on this analysis, the correct answer is: Statement I is true but Statement II is false.
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: