Q. You are provided with one low resistance $R_L$ and one high resistance $R_H$ and two galvanometers. One galvanometer is to be converted to an ammeter and the other to a voltmeter. Show how you will do this with the help of simple, labelled diagrams

Q.

Q. Name the series of lines in the hydrogen spectrum which lies in the ultra-violet region:

Q. Give an example where energy is converted into matter

Q. What is Modulation? Explain in brief

Q. Plot a labelled graph to show variation of thermo-emf ${}^{\prime }{e}^{\prime }$ versus temperature difference ${}^{\prime }{\theta }^{\prime }$ between the two junctions of a thermocouple. Mark ${}^{\prime }{N}^{\prime }$ as neutral temperature and ${}^{\prime }{I}^{\prime }$ as temperature of inversion

Q. What is the shape of the wavefront diverging from a point source of light?

Q. In an astronomical telescope of refracting type:

1. Eyepiece has greater focal length
2. Objective has greater focal length
3. Objective and eyepiece have equal focal length
4. Eyepiece has greater aperture than the objective

Q. Write an expression (derivation not required) for intensity of electric field of an electric dipole, in terms of its length $\left(2a\right)$, dipole moment $\left(p\right)$ and distance $\left(r\right)$ for:
$\left(1\right)$ Axial position.
$\left(2\right)$ Broad side position.

Q. Fill in the blank in the given nuclear reaction:
__________ ${+}_{13}^{27}Al{\to }_{12}^{25}Mg{+}_2^{4}He$

Q. Three capacitors $C_1=6\mu F,C_2=12\mu F$ and $C_3=20\mu F$ are connected to a $100V$ battery, as shown following figure below:
Calculate:
Electrostatic potential energy stored in capacitor $C_3$

Q. Five resistors are connected as shown in adjoining figure.
The effective resistance i.e., equivalent resistance between the points $A$ and $B$ is

1. $5\Omega$
2. $15\Omega$
3. $20\Omega$
4. $4\Omega$

Q. The critical angle for a given transparent medium and air is $i_c$. A ray of light travelling in air is incident on this transparent medium at an angle of incident equal to the polarising angle $i_p$. What is the relation between the two angles $i_c$ and $i_p$?

Q. ${}^{\prime }{n}^{\prime }$ cells, each of emf ${}^{\prime }{e}^{\prime }$ and internal resistance ${}^{\prime }{r}^{\prime }$ are joined in series to form a row. ${}^{\prime }{m}^{\prime }$ such rows are connected in parallel to form a battery of $N=mn$ cells. This battery is connected to an external resistance ${}^{\prime }{R}^{\prime }$
Show that current ${}^{\prime }{I}^{\prime }$ flowing through the external resistance ${}^{\prime }{R}^{\prime }$ is given by:
$I=\frac{Ne}{mR+nr}$

Q. The Biot Savart's Law in vector form is

1. $\overline{\delta B}=\frac{{\mu }_0}{4\pi }\frac{dl(\overrightarrow{l}\times \overrightarrow{r})}{r^3}$
2. $\overline{\delta B}=\frac{{\mu }_0}{4\pi }\frac{I(\overrightarrow{dl}\times \overrightarrow{r})}{r^3}$
3. $\overline{\delta B}=\frac{{\mu }_0}{4\pi }\frac{I(\overrightarrow{r}\times \overrightarrow{dl})}{r^3}$
4. $\overline{\delta B}=\frac{{\mu }_0}{4\pi }\frac{I(\overrightarrow{dl}\times \overrightarrow{r})}{r^2}$

Q. Alternating current flowing through a certain electrical device leads over the potential difference across it by ${90}^{\circ }$. State whether this device is a resistor, capacitor or an inductor

Q. Relative permittivity of water is $81$. If ${ϵ}_w$ and ${ϵ}_0$ are permittivities of water and vacuum respectively, then :

1. ${ϵ}_0=9{ϵ}_w$
2. ${ϵ}_0=81{ϵ}_w$
3. ${ϵ}_w=9{ϵ}_0$
4. ${ϵ}_w=81{ϵ}_0$

Q. In the circuit shown in figure belwo, $E_1=17V,E_2=21V,R_1=2\Omega ,R_{2}3\Omega$ and $R_3=5\Omega$. Using Kirchhoff's laws, find the currents flowing through the resistors $R_1,R_2$ and $R_3$. (Internal resistance of each of the batteries is negligible)

Q. The particles which cannot be accelerated by a cyclotron or a Van de Graff generator are :

1. alpha particles
2. beta particles
3. neutrons
4. protons

Q. A large hollow metallic sphere has a positive charge of $35.4\mu C$ at its centre. Find how much electric flux will emanate from the sphere ?

Q. Find the focal length and nature of a lens whose optical power is $-5D$

Q. What is Peltier effect?

Q. What are the dark lines seen in the solar spectrum called?

Q. State the $SI$ unit of magnetic dipole moment

Q. To convert a pure semiconductor into n-type semi-conductor, what type of impurity is added to it?

Q. What is the relation between wavelength and momentum of moving particles?

Q. Name any one instrument which works on the principle of tangent law in magnetism

Q. A current '$I$' flows through a metallic wire of radius '$r$' and the free electrons in it drift with a velocity $v_d$. Calculate the drift velocity of the free electrons through the wire of the same material, having double the radius, when some current flows through it.

Q. Three capacitors $C_1=6\mu F,C_2=12\mu F$ and $C_3=20\mu F$ are connected to a $100V$ battery, as shown following figure below:
Calculate:
Charge on each plate of capacitor $C_1$

Q. ${}^{\prime }{n}^{\prime }$ cells, each of emf ${}^{\prime }{e}^{\prime }$ and internal resistance ${}^{\prime }{r}^{\prime }$ are joined in series to form a row. ${}^{\prime }{m}^{\prime }$ such rows are connected in parallel to form a battery of $N=mn$ cells. This battery is connected to an external resistance ${}^{\prime }{R}^{\prime }$
What is the emf of this battery and how much is its internal resistance?