1. \(1.59\)
2. \(1.69\)
3. \(1.78\)
4. \(1.25\)
A beam of light from a source \(L\) is incident normally on a plane mirror fixed at a certain distance \(x\) from the source. The beam is reflected back as a spot on a scale placed just above the source \(L.\) When the mirror is rotated through a small angle \(\theta,\) the spot of the light is found to move through a distance \(y\) on the scale. The angle \(\theta\) is given by:
| 1. | \(\dfrac{y}{x}\) | 2. | \(\dfrac{x}{2y}\) |
| 3. | \(\dfrac{x}{y}\) | 4. | \(\dfrac{y}{2x}\) |
If \(\phi_1\) and \(\phi_2\) are the apparent angles of dip observed in two vertical planes at right angles to each other, then the true angle of dip \(\phi\) is given by:
1. \(cos^2{\phi}=cos^2{\phi_1}+cos^2{\phi_2}\)
2. \(sec^2{\phi}=sec^2{\phi_1}+sec^2{\phi_2}\)
3. \(tan^2{\phi}=tan^2{\phi_1}+tan^2{\phi_2}\)
4. \(cot^2{\phi}=cot^2{\phi_1}+cot^2{\phi_2}\)
Two cars moving in opposite directions approach each other at speeds of 22 m/s and 16.5 m/s, respectively. The driver of the first car blows a horn with a frequency of 400 Hz. The frequency heard by the driver of the second car is [assume velocity of sound to be 340 m/s]:
1. 361 Hz
2. 411 Hz
3. 448 Hz
4. 350 Hz
A massless and inextensible string connects two blocks \(\mathrm{A}\) and \(\mathrm{B}\) of masses \(3m\) and \(m,\) respectively. The whole system is suspended by a massless spring, as shown in the figure. The magnitudes of acceleration of \(\mathrm{A}\) and \(\mathrm{B}\) immediately after the string is cut, are respectively:
| 1. | \(\dfrac{g}{3},g\) | 2. | \(g,g\) |
| 3. | \(\dfrac{g}{3},\dfrac{g}{3}\) | 4. | \(g,\dfrac{g}{3}\) |
A thin prism having refracting angle \(10^\circ\) is made of glass of a refractive index \(1.42\). This prism is combined with another thin prism of glass with a refractive index \(1.7\). This combination produces dispersion without deviation. The refracting angle of the second prism should be:
| 1. | \(6^{\circ}\) | 2. | \(8^{\circ}\) |
| 3. | \(10^{\circ}\) | 4. | \(4^{\circ}\) |
The acceleration due to gravity at a height \(1~\text{km}\) above the earth's surface is the same as at a depth \(d\) below the surface of the earth. Then:
| 1. | \(d= 1~\text{km}\) | 2. | \(d= \frac{3}{2}~\text{km}\) |
| 3. | \(d= 2~\text{km}\) | 4. | \(d= \frac{1}{2}~\text{km}\) |
A potentiometer is an accurate and versatile device to make electrical measurements of E.M.F. because the method involves:
| 1. | the potential gradients. |
| 2. | a condition of no current flow through the galvanometer. |
| 3. | a condition of cells, galvanometer, and resistances. |
| 4. | the cells. |
1. \(450\)
2. \(1000\)
3. \(1800\)
4. \(225\)
The figure shows a circuit that contains three identical resistors with resistance \(R = 9.0~\Omega\) each, two identical inductors with inductance \(L = 2.0~\text{mH}\) each, and an ideal battery with emf \(\varepsilon = 18~\text{V}\). The current \('i'\) through the battery just after the switch is closed will be:
1. \(0.2~\text{A}\)
2. \(2~\text{A}\)
3. \(4~\text{A}\)
4. \(2~\text{mA}\)
© 2026 GoodEd Technologies Pvt. Ltd.