Answer:
C. Replacing one gas by another under the same conditions, has no effect on pressure.
Explanation:
Ideal gas:
A gas is treated as an ideal gas if temperature is high and pressure is low.
Kinetic energy for ideal gas given as

So when temperature of gas is increases then Average molecular kinetic energy will also increases.
The size of molecule is negligible as compare to the dimension of container. It mean that volume occupied by molecule is less as compare to the volume of container.
The between molecules is perfectly elastic.
Ideal gas equation
P V = m R T
So the option C is not always true.
Answer:
The velocity is 
Explanation:
From the question we are told that
The diameter of the pipe is 
The magnetic field is 
The hall voltage is 
Generally the average fluid velocity is mathematically represented as

=> 
=> 
Answer:
Speed of the ball relative to the boys: 25 km/h
Speed of the ball relative to a stationary observer: 35 km/h
Explanation:
The RV is travelling at a velocity of

Here we have taken the direction of motion of the RV as positive direction.
The boy sitting near the driver throws the ball back with speed of 25 km/h, so the velocity of the ball in the reference frame of the RV is

with negative sign since it is travelling in the opposite direction relative to the RV. Therefore, this is the velocity measured by every observer in the reference frame of the RV: so the speed measured by the boys is
v = 25 km/h
Instead, a stationary observer outside the RV measures a velocity of the ball given by the algebraic sum of the two velocities:
v = +60 km/h + (-25 km/h) = +35 km/h
So, he/she measures a speed of 35 km/h.
Left and right to a point called ad focal point after passing through convex lens