The diagrams below show regions of equipotential.

A positive charge is moved from \(A\) to \(B\) in each diagram. Choose the correct statement from the options given below:
| 1. | in all four cases, the work done is the same. |
| 2. | minimum work is required to move \(q\) in figure \(\mathrm{(a)}.\) |
| 3. | maximum work is required to move \(q\) in figure \(\mathrm{(b)}.\) |
| 4. | maximum work is required to move \(q\) in figure \(\mathrm{(c)}.\) |
Two astronauts are floating in gravitation-free space after having lost contact with their spaceship. The two will:
| 1. | move towards each other. |
| 2. | move away from each other. |
| 3. | become stationary. |
| 4. | keep floating at the same distance between them. |
The \(x\) and \(y\) coordinates of the particle at any time are \(x=5 t-2 t^2\) and \({y}=10{t}\) respectively, where \(x\) and \(y\) are in meters and \(\mathrm{t}\) in seconds. The acceleration of the particle at \(\mathrm{t}=2\) s is:
| 1. | \(5\hat{i}~\text{m/s}^2\) | 2. | \(-4\hat{i}~\text{m/s}^2\) |
| 3. | \(-8\hat{j}~\text{m/s}^2\) | 4. | \(0\) |
One end of the string of length \(l\) is connected to a particle of mass \(m\) and the other end is connected to a small peg on a smooth horizontal table. If the particle moves in a circle with speed \(v\), the net force on the particle (directed towards the center) will be: (\(T\) represents the tension in the string)
| 1. | \(T+\dfrac{m v^2}{l}\) | 2. | \(T-\dfrac{m v^2}{l}\) |
| 3. | zero | 4. | \(T\) |
A particle executes linear simple harmonic motion with amplitude of \(3~\text{cm}\). When the particle is at \(2~\text{cm}\) from the mean position, the magnitude of its velocity is equal to that of its acceleration. Then its time period in seconds is:
1. \(\dfrac{\sqrt5}{2\pi}\)
2. \(\dfrac{4\pi}{\sqrt5}\)
3. \(\dfrac{4\pi}{\sqrt3}\)
4. \(\dfrac{\sqrt5}{\pi}\)
Two polaroids \(P_1\) and \(P_2\) are placed with their axis perpendicular to each other. Unpolarised light of intensity \(I_0\) is incident on \(P_1\). A third polaroid \(P_3\) is kept in between \(P_1\) and \(P_2\) such that its axis makes an angle \(45^\circ\) with that of \(P_1\). The intensity of transmitted light through \(P_2\) is:
1. \(\dfrac{I_0}{4}\)
2. \(\dfrac{I_0}{8}\)
3. \(\dfrac{I_0}{16}\)
4. \(\dfrac{I_0}{2}\)
The bulk modulus of a spherical object is \(B.\) If it is subjected to uniform pressure \(P,\) the fractional decrease in radius is:
| 1. | \(\frac{B}{3P}\) | 2. | \(\frac{3P}{B}\) |
| 3. | \(\frac{P}{3B}\) | 4. | \(\frac{P}{B}\) |
In an electromagnetic wave in free space, the root mean square value of the electric field is \(E_{\text{rms}} = 6~\text{V/m}\). The peak value of the magnetic field is:
1. \(2.83\times 10^{-8}~\text{T}\)
2. \(0.70\times 10^{-8}~\text{T}\)
3. \(4.23\times 10^{-8}~\text{T}\)
4. \(1.41\times 10^{-8}~\text{T}\)
| 1. | \(0.25 ~\text{rad/s}^2 \) | 2. | \(25 ~\text{rad/s}^2 \) |
| 3. | \(5 ~\text{m/s}^2 \) | 4. | \(25 ~\text{m/s}^2 \) |
Two discs of the same moment of inertia are rotating about their regular axis passing through centre and perpendicular to the plane of the disc with angular velocities \(\omega_1\) and \(\omega_2\). They are brought into contact face to face with their axis of rotation coinciding. The expression for loss of energy during this process is:
1. \(\frac{1}{4}I\left(\omega_1-\omega_2\right)^2\)
2. \(I\left(\omega_1-\omega_2\right)^2\)
3. \(\frac{1}{8}I\left(\omega_1-\omega_2\right)^2\)
4. \(\frac{1}{2}I\left(\omega_1-\omega_2\right)^2\)