1. Ans:

To calculate the number of turns in the secondary coil of a transformer used to charge a 12 V rickshaw, we can use the transformer equation relating the primary and secondary voltages and turns:

$\frac{ N_p}{N_s}$ = $\frac{ V_p}{V_s}$

Given:

Number of primary coils ( \(\rm N_p\) )= \(\rm 550\) 

Number of secondary coils ( \(\rm N_s\))=  \(\rm ?\) 

Primary Voltage( \(\rm V_p\) )=  \(\rm 220V\) 

Secondary Voltage( \(\rm V_s\) )=  \(\rm 12V\) 

\(\rm or, \) $\frac{ 550}{N_s}$ = $\frac{220}{12}$

\(\rm or, \) $\frac{ 550.12}{220}$ = \(\rm N_s \) 

\(\rm or, \) \(\rm N_s \)   = $\frac{ 6600}{220}$

\(\rm or, \) \(\rm N_s \)   = \(\rm 30 \) 

Thus, the number of turns in the secondary coil is 30 turns.

2.Ans:

The transformer used to charge the rickshaw is a step-down transformer. This type reduces the voltage from a higher level (220 V) to a lower level (12 V) suitable for charging the rickshaw's battery. 

The transformer used in power house however is a step-up transformer. This type increases the voltage from a lower level to higher level.

One key difference between this step-down transformer and transformers typically used in powerhouses is their function:

• Step-down transformers like the one used for charging e-rickshaws are designed to reduce high voltages to lower levels for safe usage.
• Step-up transformers in powerhouses are often used to increase voltage levels for efficient long-distance transmission of electricity.