| 1. | \(2.5\times 10^{8}~\text{m/s}\) | 2. | \(3\times 10^{8}~\text{m/s}\) |
| 3. | \(2.08\times 10^{8}~\text{m/s}\) | 4. | \(4.32\times 10^{8}~\text{m/s}\) |
A sphere encloses an electric dipole with charges \(\pm3\times10^{-6}~\text C.\) What is the total electric flux through the sphere?
1. \(-3\times10^{-6}~\text{N-m}^2/\text C\)
2. zero
3. \(3\times10^{-6}~\text{N-m}^2/\text C\)
4. \(6\times10^{-6}~\text{N-m}^2/\text C\)
Two identical capacitors \(C_{1}\) and \(C_{2}\) of equal capacitance are connected as shown in the circuit. Terminals \(a\) and \(b\) of the key \(k\) are connected to charge capacitor \(C_{1}\) using a battery of emf \(V\) volt. Now disconnecting \(a\) and \(b\) terminals, terminals \(b\) and \(c\) are connected. Due to this, what will be the percentage loss of energy?
1. \(75\%\)
2. \(0\%\)
3. \(50\%\)
4. \(25\%\)
The main scale of a vernier calliper has \(n\) divisions/cm. \(n\) divisions of the vernier scale coincide with \((n-1)\) divisions of the main scale. The least count of the vernier calliper is:
| 1. | \(\dfrac{1}{(n+1)(n-1)}\) cm | 2. | \(\dfrac{1}{n}\) cm |
| 3. | \(\dfrac{1}{n^{2}}\) cm | 4. | \(\dfrac{1}{(n)(n+1)}\) cm |
| 1. | \(\dfrac{1}{v} = \dfrac{1}{v_1}+\dfrac{1}{v_2}\) | 2. | \(\dfrac{2}{v} = \dfrac{1}{v_1}+\dfrac{1}{v_2}\) |
| 3. | \(\dfrac{v}{2} = \dfrac{v_1+v_2}{2}\) | 4. | \(v = \sqrt{v_1v_2}\) |
Assuming that the gravitational potential energy of an object at infinity is zero, the change in potential energy (final - initial) of an object of mass \(m\) when taken to a height \(h\) from the surface of the earth (of radius \(R\) and mass \(M\)), is given by:
| 1. | \(-\frac{GMm}{R+h}\) | 2. | \(\frac{GMmh}{R(R+h)}\) |
| 3. | \(mgh\) | 4. | \(\frac{GMm}{R+h}\) |
\(1~\text g\) of water of volume \(1~\text{cm}^3\) at \(100^\circ \text{C}\) is converted into steam at the same temperature under normal atmospheric pressure \(\approx 1\times10^{5}~\text{Pa}.\) The volume of steam formed equals \(1671~\text{cm}^3.\) If the specific latent heat of vaporization of water is \(2256~\text{J/g},\) the change in internal energy is:
| 1. | \(2423~\text J\) | 2. | \(2089~\text J\) |
| 3. | \(167~\text J\) | 4. | \(2256~\text J\) |
The angular width of the central maximum in the Fraunhofer diffraction for \(\lambda=6000~{\mathring{A}}\) is \(\theta_0.\) When the same slit is illuminated by another monochromatic light, the angular width decreases by \(30\%.\) The wavelength of this light is:
1. \(1800~{\mathring{A}}\)
2. \(4200~{\mathring{A}}\)
3. \(420~{\mathring{A}}\)
4. \(6000~{\mathring{A}}\)
The work function of the photosensitive material is \(4.0~\text{eV}\). The longest wavelength of light that can cause photoelectric emission from the substance is (approximately):
1. \(3100~\text{nm}\)
2. \(966~\text{nm}\)
3. \(31~\text{nm}\)
4. \(310~\text{nm}\)
A proton and an \(\alpha\text{-}\)particle are accelerated from rest to the same energy. The de-Broglie wavelength \(\lambda_p\) and \(\lambda_\alpha\) are in the ratio:
1. \(2:1\)
2. \(1:1\)
3. \(\sqrt{2}:1\)
4. \(4:1\)
© 2026 GoodEd Technologies Pvt. Ltd.