Q. A star is moving away from the Earth with speed $V$. Change in wavelength $\left(d\lambda \right)$ observed on Earth is.

1. $\lambda V/C$
2. $\lambda V/(C+V)$
3. $\lambda C/(C+V)$
4. $\lambda C/V$

Q. Electrons are excited form $n=1$ to $n=4$ state. During downward transitions, possible number of spectral lines observed in Balmer series is.

1. $2$
2. $4$
3. $3$
4. $1$

Q. Carnot's heat engine takes $300J$ of heat from a source at ${627}^{\circ }C$ and gives some part of it to sink at ${27}^{\circ }C$. Work done by engine in one cycle is.

1. $200J$
2. $300J$
3. $150J$
4. $120J$

Q. Material of permanent magnet has:

1. High retentivity and high coercivity
2. Low retentivity and high coercivity
3. Low retentivity and low coercivity
4. High retentivity and low coercivity

Q. $15/{16}^{th}$ of a radioactive sample disintegrates in $2hrs$. Mean life of radioactive sample is approximately.

1. $30min$
2. $43min$
3. $15min$
4. $21min$

Q. ${}_6{C}^{14}$ and ${}_7{N}^{15}$ are the examples of.

1. Mirror nuclei
2. Isobars
3. Isotones
4. Isotopes

Q. A simple pendulum has a period T inside a lift when it is stationary. The lift is accelerated upwards with constant acceleration ${}^{\prime }{a}^{\prime }$. The period.

1. Decreases
2. Increases
3. Remains same
4. Becomes infinite

Q. $90dB$ sound is ${}^{\prime }{x}^{\prime }$ times more intense than $40dB$ sound, then $x$ is

1. $5$
2. $50$
3. ${10}^5$
4. $500$

Q. It is difficult to observe diffraction in case of light waves, because

1. Light waves can travel through vacuum
2. Wavelength of light is small
3. Speed of light is more
4. Light waves are transverse in nature

Q. In Young's double slit experiment. $1st$ dark fringe occurs directly opposite to a slit. Wavelength of light used is :

1. $d^2/D$
2. $d/D$
3. $D^2/d$
4. $2d^2/D$

Q. Plane polarised light is passed through an analyser and the intensity of emerging light is reduced by $75$%. Optical vibrations make an angle $\theta$ with the axis of analyser. Then $\theta$ is.

1. ${60}^{\circ }$
2. ${45}^{\circ }$
3. ${50}^{\circ }$
4. ${58}^{\circ }$

Q. A calcite crystal is placed over a dot on a paper sheet and the crystal is rotated. On viewing through the calcite one sees

1. A single stationary dot
2. Two dots rotating about one another
3. One dot rotating about the other stationary dot-sometimes coinciding with it
4. Two stationary dots

Q. An inductor of inductance $1.2734H$ is connected across $200V50Hz$ supply. Peak value of current is approximately.

1. $0.5A$
2. $0.7A$
3. $1.4A$
4. $1A$

Q. $n$ type and $p$ type semiconductors can be obtained by doping pure silicon respectively with.

1. Arsenic Phosphorous
2. Phosphorous Indium
3. Indium Aluminium
4. Aluminium Boron

Q. Particles which are not composite and hence truly elementary are.

1. Mesons
2. Protons
3. Neutrons
4. Leptons

Q. If only $2$% of the main current is to be passed through a Galvanometer of resistance $G$, the resistance of shunt should be :

1. $G/49$
2. $G/50$
3. $49G$
4. $50/G$

Q. IR region lies between.

1. Radio waves and microwave regions
2. Microwave and visible
3. Visible and UV region
4. UV rays and X-ray region

Q. A proton and an alpha particle are subjected to same potential difference $V$. Their de-Broglies wavelengths ${\lambda }_p,{\lambda }_{\alpha }$ will be in the ratio.

1. $1:2$
2. $4:1$
3. $2\sqrt{2}:1$
4. $2:1$

Q. Newton's ring pattern in reflected system, viewed under white light consists of

1. Equally spaced bright and dark bands with central dark spot
2. Equally spaced bright and dark bands with central white spot
3. A few coloured rings with central dark spot
4. A few coloured rings with central white spot

Q. Power factor of a series $LCR$ circuit is

1. $R$
2. $RZ$
3. $R/Z$
4. $Z/R$

Q. A logic gate whose output will be in logic $0$ state only when all inputs are in logic $1$ state is called.

1. AND
2. OR
3. NOR
4. NAND

Q. An open pipe emits a fundamental frequency $n_0$ when it emits the $3^{rd}$ harmonic, the pipe can accommodate.

1. $2$ nodes $2$ antinodes
2. $3$ nodes $4$ antinodes
3. $3$ nodes $3$ antinodes
4. $1$ node $2$ antinodes

Q. Two concentric circular coils, each having $10$ turns with radii $0.2m$ and $0.4m$ carry currents $0.2A$ and $0.3A$ respectively in opposite direction. Magnetic field at the centre is

1. $\left(5/4\right){\mu }_0$
2. $\left(2/3\right){\mu }_0$
3. $\left(1/4\right){\mu }_0$
4. $\left(1/6\right){\mu }_0$

Q. In an adiabatic process.

1. Temperature remains constant
2. Pressure remains constant
3. There is no transfer of heat
4. Volume remains constant

Q. In a $CE$ amplifier $\beta =50,R_L=4K\Omega .R_1=500\Omega$. Power gain of the amplifier is.

1. $2\times {10}^4$
2. $2\times {10}^3$
3. $2\times {10}^2$
4. $2\times {10}^1$

Q. Clear images of soft tissues can be well studied using.

1. MRI
2. Ultrasonics
3. I.R rays
4. X-rays

Q. 'Raman Shift' depends on.

1. Incident intensity
2. Resolving power of the spectrograph used
3. Incident wavelenght
4. Molecular energy levels of the scatterer.

Q. A small current carrying loop of area $A$ behaves like a tiny magnet of magnetic moment $M$. Current in the loop is

1. $MA$
2. $A^{2}M$
3. $A/M$
4. $M/A$

Q. Critical angle of the medium is ${45}^{\circ }$, Polarising angle of incidence at the surface of the medium is

1. ${45}^{\circ }$
2. ${38}^{\circ }$
3. ${22.5}^{\circ }$
4. ${54.7}^{\circ }$

Q. In an interference experiment, intensity ratio at the bright to dark fringe is $9:1$. Amplitudes of interfering waves was in the ratio.

1. $3:1$
2. $2:1$
3. $9:1$
4. $4:1$