NEET Questions

The value of $\frac{4.0 imes 10^{-2} imes 0.00302}{200.0}$ expressed with the correct number of significant figures is:

A student performs an experiment to determine the density of a rectangular block. They measure the length as $12.12 ext{ cm}$, the width as $5.3 ext{ cm}$, and the height as $1.21 ext{ cm}$. The mass is measured as $50.2 ext{ g}$. The student calculates the volume and then the density. Which of the following correctly expresses the final calculated density with the appropriate number of significant figures?

A student calculates the volume of a sphere to be $4.1887902047863905 imes 10^3 cm^3$. If the radius measurement used in the calculation has only two significant figures, what is the correctly rounded volume?

A boy throws a ball of mass 0.5 kg with a velocity of 10 m/s to the east. What is the momentum of the ball?

An object has a kinetic energy of 10 J. If its mass is 2 kg, what is its speed?

In a Wheatstone bridge, if the resistances are P = 10 Ω, Q = 20 Ω, R = 30 Ω, and the bridge is balanced, what is the value of S?

If the radius of a nucleus is $1.4 imes 10^{-15}$ m, and the radius of the atom is $1.4 imes 10^{-10}$ m, approximately what fraction of the atom's volume is occupied by the nucleus?

A buffer solution is prepared by mixing 20 mL of 0.1 M CH$_3$COOH and 30 mL of 0.2 M CH$_3$COONa. To this mixture, 1 mL of 1 M NaOH is added. The pH change of the buffer is closest to (pK$_a$ of CH$_3$COOH = 4.74):

100 mL of a buffer solution contains 0.1 M NH$_4$OH and 0.1 M NH$_4$Cl. If K$_b$ for NH$_4$OH is 1.8 x 10$^{-5}$, what is the pH change when 0.01 moles of HCl are added?

A buffer solution with pH 9 is to be prepared using NH$_4$OH (K$_b$= 1.8 x 10$^{-5}$) and NH$_4$Cl. What should be the ratio of [NH$_4$Cl]/[NH$_4$OH]?