| 1. | \(0.125\times10^{-3}~\text{C m}^{-2}\) | 2. | \(0.25\times10^{-3}~\text{C m}^{-2}\) |
| 3. | \(4\times10^{-3}~\text{C m}^{-2}\) | 4. | \(0.4\times10^{-3}~\text{C m}^{-2}\) |
| 1. | \(10^{20}\) | 2. | \(10^{30}\) |
| 3. | \(10^{40}\) | 4. | \(10\) |
The acceleration of an electron due to the mutual attraction between the electron and a proton when they are \(1.6~\mathring{A}\) apart is:
\(\left(\dfrac{1}{4 \pi \varepsilon_0}=9 \times 10^9~ \text{Nm}^2 \text{C}^{-2}\right)\)
1. \( 10^{24} ~\text{m/s}^2\)
2. \( 10^{23} ~\text{m/s}^2\)
3. \( 10^{22}~\text{m/s}^2\)
4. \( 10^{25} ~\text{m/s}^2\)
| 1. | \(\frac{4F}{3}\) | 2. | \(F\) |
| 3. | \(\frac{9F}{16}\) | 4. | \(\frac{16F}{9}\) |
Suppose the charge of a proton and an electron differ slightly. One of them is \(-e,\) the other is \((e+\Delta e).\) If the net of electrostatic force and gravitational force between two hydrogen atoms placed at a distance \(d\) (much greater than atomic size) apart is zero, then \(\Delta e\) is of the order of?
(Given the mass of hydrogen \(m_h = 1.67\times 10^{-27}~\text{kg}\))
1. \(10^{-23}~\text{C}\)
2. \(10^{-37}~\text{C}\)
3. \(10^{-47}~\text{C}\)
4. \(10^{-20}~\text{C}\)
| 1. | \(\dfrac{-Q}{4}\) | 2. | \(\dfrac{Q}{4}\) |
| 3. | \(\dfrac{-Q}{2}\) | 4. | \(\dfrac{Q}{2}\) |
| 1. | \(\dfrac{r}{\sqrt[3]{2}}\) | 2. | \(\dfrac{r}{\sqrt[2]{2}}\) |
| 3. | \(\dfrac{2r}{3}\) | 4. | none of the above |
| 1. | \(2 ~\text{NC}^{-1}\) | 2. | \(1~\text{NC}^{-1}\) |
| 3. | \(0.5~\text{NC}^{-1}\) | 4. | zero |
| 1. | \(\dfrac{Eqm}{t}\) | 2. | \(\dfrac{E^2q^2t^2}{2m}\) |
| 3. | \(\dfrac{2E^2t^2}{qm}\) | 4. | \(\dfrac{Eq^2m}{2t^2}\) |