\(M_p\) denotes the mass of a proton and \(M_n\) that of a neutron. A given nucleus, of binding energy \(B\), contains \(Z\) protons and \(N\) neutrons. The mass \(M(N,Z)\) of the nucleus is given by:
(\(c\) is the velocity of light )
1. \(M(N,Z)= NM_n+ZM_p+ Bc^2\)
2. \(M(N,Z)= NM_n+ZM_p-\frac{B}{c^2}\)
3. \(M(N,Z)= NM_n+ZM_p+\frac{B}{c^2}\)
4. \(M(N,Z)= NM_n+ZM_p- Bc^2\)
A telescope has an objective lens of 10 cm diameter and is situated at a distance of one kilometre from two objects. The minimum distance between these two objects, which can be resolved by the telescope, when the mean wavelength of light is 5000 Å, is of the order of:
1. 5 m
2. 5 mm
3. 5 cm
4. 0.5 m
The phase difference between two waves, represented by
\(y_1= 10^{-6}\sin \left\{100t+\left(\frac{x}{50}\right) +0.5\right\}~\text{m}\)
\(y_2= 10^{-6}\cos \left\{100t+\left(\frac{x}{50}\right) \right\}~\text{m}\)
where \(x\) is expressed in metres and \(t\) is expressed in seconds, is approximate:
1. \(2.07~\text{radians}\)
2. \(0.5~\text{radians}\)
3. \(1.5~\text{radians}\)
4. \(1.07~\text{radians}\)
A block of mass \(m\) is placed on a smooth wedge of inclination \(\theta\). The whole system is accelerated horizontally so that the block does not slip on the wedge. The force exerted by the wedge on the block (\(g\) is the acceleration due to gravity) will be:
1. \(mg~\mathrm{sin\theta}\)
2. \(mg\)
3. \(\frac{mg}{\mathrm{cos\theta}}\)
4. \(mg~\mathrm{cos\theta}\)
Three particles, each of mass \(m\) gram, are situated at the vertices of an equilateral triangle ABC of side \(l\) cm (as shown in the figure). The moment of inertia of the system about a line AX, perpendicular to AB and in the plane of ABC, in gram-cm2 units will be:
1. \(2ml^2\)
2. \(\frac{5}{4}ml^2\)
3. \(\frac{3}{2}ml^2\)
4. \(\frac{3}{4}ml^2\)
Energy \(E\) of a hydrogen atom with principal quantum number \(n\) is given by \(E=-\frac{13.6}{n^{2}}~\text{eV}.\) The energy of a photon ejected when the electron jumps from \(n=3\) state to \(n=2\) state of hydrogen is approximately:
1. \(0.85~\text{eV}\)
2. \(3.4~\text{eV}\)
3. \(1.9~\text{eV}\)
4. \(1.5~\text{eV}\)
A wheel having a moment of inertia of \(2\) kg–m2 about its vertical axis rotates at the rate of \(60\) rpm about the axis. The torque which can stop the wheel's rotation in one minute would be:
| 1. | \(\dfrac{\pi }{12}\) N-m | 2. | \(\dfrac{\pi }{15}\) N-m |
| 3. | \(\dfrac{\pi }{18}\) N-m | 4. | \(\dfrac{2\pi }{15}\) N-m |
Consider a system of two particles having masses m1 and m2. If the particle of mass m1 is pushed towards the mass centre of particles through a distance 'd', by what distance would the particle of mass m2 move so as to keep the mass centre of particles at the original position ?
1.
2. d
3.
4.
The coefficient of static friction, \(\mu_s,\) between block A of mass \(2\) kg and the table as shown in the figure is \(0.2\). What would be the maximum mass value of block B so that the two blocks do not move? The string and the pulley are assumed to be smooth and massless. (take \(g=10\) m/s2 )
1. \(4.0\) kg
2. \(0.2\) kg
3. \(0.4\) kg
4. \(2.0\) kg