NEET 1990 Physics Paper: AIPMT

Consider an electron in the $n$th orbit of a hydrogen atom in the Bohr model. The circumference of the orbit can be expressed in terms of de Broglie wavelength $\lambda$ of that electron as

Energy levels $A,\ B$ and $C$ of a certain atom corresponding to increasing values of energy i.e. $E_{A} < E_{B} < E_{C}$. If $\lambda_{1},\ \lambda_{2}$ and $\lambda_{3}$ are wavelengths of radiations corresponding to transitions $C$ to $B,\ B$ to $A$ and $C$ to $A$ respectively, which of the following relations is correct?

The valence electron in alkali metal is a

Two identical batteries each of e.m.f $2\text{ V}$ and internal resistance $1\ \Omega$ are available to produce heat in an external resistance by passing a current through it. The maximum power that can be developed across $R$ using these batteries is

You are given several identical resistances each of value $R = 10\ \Omega$ and each capable of carrying a maximum current of one ampere. It is required to make a suitable combination of these resistances of $5\ \Omega$ which can carry a current of 4 ampere. The minimum number of resistances of the type $R$ that will be required for this job is

In the network shown in figure each resistance is $1\ \Omega$. The effective resistance between $A$ and $B$ is

In which of the following, emission of electrons does not take place

The momentum of a photon of an electromagnetic radiation is $3.3 \times 10^{-29}\text{ kg ms}^{-1}$. What is the frequency of the associated waves?

[$h = 6.6 \times 10^{-34}\text{ Js}$; $c = 3 \times 10^{8}\text{ ms}^{-1}$]

A radio transmitter operates at a frequency 880 kHz and a power of 10 kW. The number of photons emitted per second is

The current in self inductance $L = 40\text{ mH}$ is to be increased uniformly from 1 amp to 11 amp in 4 milliseconds. The e.m.f. induced in inductor during process is

An inductor may store energy in

A planet is moving in an elliptical orbit around the sun. If $T$, $V$, $E$ and $L$ stand respectively for its kinetic energy, gravitational potential energy, total energy and magnitude of angular momentum about the centre of force, which of the following is correct?

According to kinetic theory of gases, at absolute zero of temperature

A $600\text{ kg}$ rocket is set for a vertical fring. If the exhaust speed is $1000\text{ m s}^{-1}$, the mass of the gas ejected per second to supply the thrust needed to overcome the weight of rocket is

A car covers the first half of the distance between two places at 40 km/h and another half at 60 km/h. The average speed of the car is

The magnetic induction at a point $P$ which is at the distance of $4\text{ cm}$ from a long current carrying wire is $10^{-3}\text{ T}$. The field of induction at a distance $12\text{ cm}$ from the current will be

The nuclei ${}_{6}\text{C}^{13}$ and ${}_{7}\text{N}^{14}$ can be described as

The ratio of the radii of the nuclei ${}_{13}\text{Al}^{27}$ and ${}_{52}\text{Te}^{125}$ approximately

Which of the following statements is true for nuclear forces?

The nucleus ${}_{6}\text{C}^{12}$ absorbs an energetic neutron and emits a beta particle ($\beta$). The resulting nucleus is

The composition of two simple harmonic motions of equal periods at right angle to each other and with a phase difference of $\pi$ results in the displacement of the particle along

A mass $m$ is suspended from the two coupled springs connected in series. The force constant for springs are $k_1$ and $k_2$. The time period of the suspended mass will be

If a body $A$ of mass $M$ is thrown with velocity $v$ at an angle of $30^\circ$ to the horizontal and another body $B$ of the same mass is thrown with the same speed at an angle of $60^\circ$ to the horizontal, the ratio of horizontal range of $A$ to $B$ will be

The maximum range of a gun of horizontal terrain is 16 km. If $g = 10\text{ m s}^{-2}$, then muzzle velocity of a shell must be

Moment of inertia of a uniform circular disc about a diameter is $I$. Its moment of inertia about an axis perpendicular to its plane and passing through a point on its rim will be

A fly wheel rotating about fixed axis has a kinetic energy of 360 joule when its angular speed is 30 radian/sec. The moment of inertia of the wheel about the axis of rotation is

The moment of inertia of a body about a given axis is $1.2\text{ kg m}^{2}$. Initially, the body is at rest. In order to produce a rotational kinetic energy of 1500 joule, an angular acceleration of 25 radian/sec2 must be applied about that axis for a duration of

In a common base amplifier the phase difference between the input signal voltage and the output voltage is

When a triode is used as an amplifier the phase difference between the input signal voltage and the output is

For a certain gas the ratio of specific heats is given to be $\gamma = 1.5$. For this gas

One mole of an ideal gas requires 207 J heat to rise the temperature by 10 K when heated at constant pressure. If the same gas is heated at constant volume to raise the temperature by the same 10 K, the heat required is

(Given the gas constant $R = 8.3\text{ J/mole K}$)

Thermal capacity of 40 g of aluminium ($s = 0.2\text{ cal/g K}$) is

A Centigrade and a Fahrenheit thermometer are dipped in boiling water. The water temperature is lowered until the Fahrenheit thermometer registers $140^\circ\text{F}$. What is the fall in temperature as registered by the centigrade thermometer?

The frequency of vibration $f$ of a mass $m$ suspended from a spring of spring constant $k$ is given by a relation $f = am^xk^y$, where $a$ is a dimensionless constant. The values of $x$ and $y$ are

According to Newton, the viscous force acting between liquid layers of area $A$ and velocity gradient $\Delta v/\Delta Z$ is given by $F = -\eta A\frac{\Delta v}{\Delta Z}$, where $\eta$ is constant called coefficient of viscosity. The dimensional formula of $\eta$ is

Which of the following has the dimensions of pressure?

Velocity of sound waves in air is $330\text{ m/s}$. For a particular sound wave in air, a path difference of $40\text{ cm}$ is equivalent to phase difference of $1.6\pi$. The frequency of this wave is

In Young's double slit experiment, the fringe width is found to be 0.4 mm. If the whole apparatus is immersed in water of refractive index $\frac{4}{3}$, without disturbing the geometrical arrangement, the new fringe width will be

The Young's double slit experiment is performed with blue and with green light of wavelengths 4360 Å and 5460 Å respectively. If $x$ is the distance of 4th maxima from the central one, then

How much water a pump of $2\text{ kW}$ can raise in one minute to a height of $10\text{ m}$? (take $g = 10\text{ m/s}^2$)