Question

An electric iron consumer’s energy at a rate of 840 W when heating is at the maximum rate and 360 W when the heating is at the minimum,the voltage is 220 V. What are the current and the resistance in each case?

Answer 1

Answer:

answers. is 7volt current flow from iron

Answer 2

ᴡʜᴇɴ ʜᴇᴀᴛɪɴɢ ᴀᴛ ᴍᴀx ʀᴀᴛᴇ,

ᴘᴏᴡᴇʀ, ᴘ = 840ᴡ

ᴠ = 220ᴠ

ᴡᴇ ᴋɴᴏᴡ ᴘ = ᴠɪ

⇒ 840 = 220 × ɪ

⇒ ɪ = 840/220

⇒ ɪ = 4 ᴀ

ʀ = ᴠ/ɪ = 220/4 = 55 Ω

sᴏ ᴄᴜʀʀᴇɴᴛ = 4ᴀ ᴀɴᴅ ʀᴇsɪsᴛᴀɴᴄᴇ = 55Ω

ᴡʜᴇɴ ʜᴇᴀᴛɪɴɢ ᴀᴛ ᴍɪɴɪᴍᴜᴍ ʀᴀᴛᴇ,

ᴘᴏᴡᴇʀ, ᴘ = 360ᴡ

ᴠ = 220ᴠ

ᴡᴇ ᴋɴᴏᴡ ᴘ = ᴠɪ

⇒ 360 = 220 × ɪ

⇒ ɪ = 360/220

⇒ ɪ = 1.636 ᴀ

ʀ = ᴠ/ɪ = 220/1.636 = 134.45 Ω

sᴏ ᴄᴜʀʀᴇɴᴛ = 1.636ᴀ ᴀɴᴅ ʀᴇsɪsᴛᴀɴᴄᴇ = 134.45Ω