Question

Could Someone help me with these two problems please!

Answer 1

Question 1.

A stereo with a resistance of 65 Ω is connected across a potential difference of 140 V. What is the current in this device?

Answer :-

Resistance = 65 Ω

Potential difference = 140V

• I = V/R

where, I denotes Current, V denotes potential difference and R denotes the resistance

substituting the values,

`\: :\implies` I = 140/65

`\: :\implies` I = 2.15 Ampere

Therefore, 2.15 ampere is the required current in the device.

Question 2

A 1150 W electric toaster operates on a household circuit of 100 V. What is the resistance of the wire that makes up the heating element of the toaster?

Answer :-

• Power = 1150 W
• Potential difference = 100 V

We know that,

• P = IV

where, P denotes Power , I denotes Current and V denotes the potential difference.

Substituting the values,

`\: :\implies` 1150 = I × 110

`\: :\implies` 1150/100 = I

`\: :\implies` 11.5 = I

Required current = 11.5 A

Now,

• R = V/I

where, R denotes resistance, V denotes potential difference

and I denotes the Current.

Substituting the values,

`\: :\implies` R = 110/1.5

`\: :\implies` R = 8.69 Ω

Therefore, 8.69Ω is the required resistance of the wire that makes up the heating element of the toaster