List in a tabular form two differences between a voltmeter and an ammeter.
Voltmeter | Ammeter |
$(a)$ Used to measure potential difference. | $(a)$ Used to measure current. |
$(b)$ Connected in parallel in an electric circuit. | $(b)$ Connected in series in the electric circuit. |
$(c)$ Has high resistance. | $(c)$ Has low resistance. |
$(a)$ What is the total resistance of $n$ resistors each of resistance ' $R^{\prime}$ connected in
$(i)$ series ?
$(ii)$ parallel ?
$(b)$ Calculate the resultant resistance of $3$ resistors $3\, \Omega, 4\, \Omega$ and $12\, \Omega$ connected in parallel.
An electric bulb rated $220 \,V , 60\, W$ is working at full efficiency.
$(i)$ State the resistance of the coil of the bulb. Another identical bulb is connected in series with the first one and the system is connected across the mains as shown below. $(ii)$ State the rate of conversion of energy in each bulb. $(iii)$ Calculate the total power. $(iv)$ What will be the total power if the bulbs are connected in parallel ?
In a household, $5$ tube lights of $40\, W$ each are used for $5$ hours and an electric press of $500 \,W$ for $4$ hour everyday. Calculate the total energy consumed by the tube lights and press in a month of $30$ days.
An electric lamp is marked $100 \,W , 220\, V$. It is used for $5$ hours daily. Calculate : $(i)$ its resistance while glowing. $(ii)$ energy consumed in $kWh$ per day.
When do we say that the resistors are connected in parallel ?