Can you think of any four devices which can work even when not connected to the switchboards at your home?

In the following passage there are blanks, each of which has been numbered. There are questions given below the passage and for each question, four words are suggested, one of which fits the blank appropriately. Find out the appropriate word in each case.

Whenever I go into a bank, I feel scared. Everybody and everything that I see there (1) ____ me. As for the manager the sight (2) ____ him simply terrifies me and (3) ____ me want to runaway (4) _____ I can. As soon as I (5) ____ the door of the bank I lose my head (6) ____ when I try to do any (7) ____ there, I behave like an idiot. I cannot explain (8) ____ for this but that is how it (9) ____ has been that is how it is (10) ____.

Select the most appropriate option for blank No. 10.

What type of energy is transformed to electrical energy in a dynamo?

Write in brief the basic principle of hydroelectric power generation.

Answer the following:

What is the frequency of household alternating current $\left(\mathrm{AC}\right)$ in India?

Write the conventional symbol of the following component used in electric circuit diagram-

An electric cell

The frequency of AC is $50 \mathrm{Hz}$.

Consider an electrical conductor connected across a potential difference $V.$ Let $\Delta q$ be a small charge moving through it in time $\Delta t$. If $I$ is the electric current through it,
(i) the kinetic energy of the charge increases by $IV\Delta t$
(ii) the electric potential energy of the charge decreases by $IV\Delta \mathrm{t}$.
(iii) the thermal energy of the conductor increases by $IV\Delta \mathrm{t}$.

Then the correct statements is/are