Question

torch bulb is rated at 3 volt and 60 ampere calculate its energy consumed if it is lighted for 4 hours​

Answer 1

P = VI

P = 3 × 60

P = 180 W

E = P × t

E = 180 × 4

E = 180/1000 × 4 ( because we want to convert it into kWh )

E = 0.72 kWh

Answer 2

$\huge{\underline{\underline{\red{\mathfrak{AnSwEr :}}}}}$

$\tt Given \begin{cases} \sf{Potential \: Difference \: (V) \: = \: 3 \: V} \\ \sf{Current \: (I) \: = \: 60 \: A} \\ \sf{Time \: (t) \: = \: 4 \: hr}\end{cases}$

We have formula for Power :

$\large \bigstar {\boxed{\sf{P \: = \: VI}}} \\ \\ \implies {\sf{P \: = \: 3 \: \times \: 60}} \\ \\ \implies {\sf{P \: = \: 180}} \\ \\ \large{\boxed{\sf{Power \: = \: 180 \: J}}}$

$\rule{100}{2}$

As we have formula for Energy Consumed :

$\large \bigstar {\boxed{\sf{E \: = \: Pt}}} \\ \\ \implies {\sf{E \: = \: 180 \: \times \: 4}} \\ \\ \implies {\sf{E \: = \: 720 \: Wh}} \\ \\ \implies {\sf{E \: = \: \dfrac{720}{1000}}} \\ \\ \implies {\sf{E \: = \: 0.72}} \\ \\ \large {\boxed{\sf{Energy \: is \: 0.72 \: KWh}}}$