# Blog

### The ratio of electric force between two electrons to two protons separated by the same distance in the air is: A B C D None of these

Correct option is (A) $10^{\circ}$ $\frac{\mathrm{F}_{\mathrm{e}}}{\mathrm{F}_{\mathrm{p}}}=10^{0}=1$, because force depends only on charges, distance and nature of medium and not type of charge. As...

### A cubic solid is made of two elements and Atoms of are at the corners of the cube and at the body-centre. What is the formula of the compound? What are the coordination numbers of and

Ans: It is given that the atoms of $\mathrm{Q}$ are present at the corners of the cube. Therefore, number of atoms of $Q$ in one unit cell $=8 \times(1 / 8)=1$ It is also given that the atoms of...

### A cubic solid is made of two elements and Atoms of are at the corners of the cube and at the body-centre. What is the formula of the compound? What are the coordination numbers of and

Ans: It is given that the atoms of $\mathrm{Q}$ are present at the corners of the cube. Therefore, number of atoms of $Q$ in one unit cell $=8 \times(1 / 8)=1$ It is also given that the atoms of...

### Copper crystallises into a fcc lattice with edge length . Show that the calculated density is in agreement with its measured value of

Ans: Edge length, $a=3.61 \times 10^{-6} \mathrm{~cm}$ As the lattice is fcc type, the number of atoms per unit cell, $z=4$ Atomic mass, $\mathrm{M}=63.5 \mathrm{~g} \mathrm{~mol}^{-1}$ We also know...

### In comparison to the electrostatic force between two electrons, the electrostatic force between two protons is : A zero B smaller c same D greater

Correct option is(c) same Since the magnitude of the charge of electron and proton is the same, e, the electrostatic force between two protons is the same compared to the electrostatic force between...

Ans: Semiconductors are substances having conductance in the intermediate range $10^{-6}$ to $10^{4}$ ohm $^{-1} \mathrm{~m}^{-1}$. The two main types of semiconductors are: (i) n-type semiconductor...