Pradeep Paul, R Parthasarthy and, Basha Solutions for Chapter: Electricity, Exercise 9: MOCK TEST - 1

Semiconductors are certain type of metals which allow only partial current to pass through in one direction only in a solar cell, the pieces of semiconductor materials containing impurities are so arranged that potential difference develops between two regions of the semiconductors when light falls on it. A lead storage battery is connected in the circuit which gets charged and can be used as and when desired. How does the conductivity of semiconductors increases?

Semiconductors are certain type of metals which allow only partial current to pass through in one direction only in a solar cell, the pieces of semiconductor materials containing impurities are so arranged that potential difference develops between two regions of the semiconductors when light falls on it. A lead storage battery is connected in the circuit which gets charged and can be used as and when desired. Name any four materials which act as a semiconductor.

What are the disadvantages of connecting two bulbs in series?

List two advantages of connecting bulbs in parallel.

As a student what initiative you can take to minimize power consumption.

(a) A current of $1$ ampere flows in a series circuit containing an electric lamp and a conductor of $5 \mathrm{\Omega }$ when connected to a $10 \mathrm{V}$ battery. Calculate the resistance of the electric lamp.
(b) Now if a resistance of $10 \mathrm{\Omega }$ is connected in parallel with this series combination, what change (if any) in current flowing through $5 \mathrm{\Omega }$ conductors and potential difference across the lamp will take place? Give reason.

A wire is connected between the point $P$ and $Q$ in the circuit to carry a current $I$. If it is replaced by a wire of same length and half thickness, how will the current vary?

A wire is connected between the point $P$ and $Q$ in the circuit to carry a current $I$. If it is replaced by a wire of Half-length and same thickness, how will the current vary?