Jatinder Singh Solutions for Chapter: Practice Papers for Revision, Exercise 3: PRACTICE PAPER - 3

Write an expression for the heat gained by ice on melting.

In a laboratory experiment for finding specific latent heat of ice, $100 \mathrm{g}$ of water at $30℃$ was taken in a calorimeter made of copper of mass $10 \mathrm{g}$. When $10 \mathrm{g}$ of ice at $0℃$ was added to the mixture and kept within the calorimeter till the ice melted completely, the final temperature of the mixture was found to be $20℃$. Specific heat capacities of water and copper being $4.2 \mathrm{J} {\mathrm{g}}^{-1} {℃}^{-1}$ and $0.4 \mathrm{J} {\mathrm{g}}^{-1} {℃}^{-1}$ respectively. Calculate the value of the latent heat of fusion of ice from the data discussed above.

Find the effective resistance between points $\mathrm{A}$ and $\mathrm{B}.$

With reference to the diagram, calculate

(i) Equivalent resistance between P and Q.

(ii) The reading of the ammeter.

(iii) The electrical power between P and Q.

The diagram shows a coil connected to a centre zero galvanometer G. The galvanometer shows a deflection to the right when the N-pole of a powerful magnet is moved to the right as shown

(i) Explain why deflection occurs in galvanometer.

(ii) Does the direction of the current in the coil appear clockwise or anticlockwise when viewed from the end A?

(iii) State the observation in G when the coil is moved away from N.

(iv) State the observation in G when both the coil and the magnet are moved to the right at the same speed.

State two factors on which the rate of emission of thermions depends on.

The isotope of ${}_{92}\mathrm{U}^{238}$ decays by alpha emission to an isotope of thorium $\left(\mathrm{Th}\right)$. The thorium isotope decays by beta emission to an isotope of protactinium $\left(\mathrm{Pa}\right)$. Write down the equation to represent these two nuclear changes.

Draw a cathode ray tube consisting of a heater, a cathode, a cylindrical anode and a deflecting system. Show how will you connect a low tension battery of $6 \mathrm{V}$ and a high tension one of $1000 \mathrm{V}$ to the electrodes of the tube.