Two lamps, one rated 100 W at 220 V , and the other 60 W at 220 V , are connected in parallel to the electric mains supply. What current is drawn from the line if the supply voltage is 220 V ?

Given, Rated power of first bulb, P 1 = 100 W and Rated voltage, V = 220 V Rated power of second bulb, P 2 = 60 W and Rated voltage, V = 220 V Resistance of the first lamp , R 1 = V 2 P 1 = 220 2 100 = 484 Ω Resistance of the second lamp, R 2 = V 2 P 2 = 220 2 60 = 806 . 67 Ω If these two resistors are joined in parallel, equivalent resistance, R e q = 484 × 806 . 67 484 + 806 . 67 Current drawn from the line , I = V R e q ⇒ I = 220 484 × 806 . 67 484 + 806 . 67 = 220 302 . 5 = 0 . 727 A

How much energy is given to each coulomb of charge passing through a 6 V battery?

The potential difference created by battery, ∆ V = 6 V The potential difference between two points in a circuit is defined as the energy required (or work done) in moving one coulomb of charge from one point to the other. ∆ V = W q , where W is work done by battery and q is the charge. ⇒ W = Δ V × q = 6 V × 1 C = 6 J

E M B I B E

SCIENCE TEXTBOOK FOR CLASS X>Chapter 12 - Electricity>QUESTIONS>Q 1

MEDIUM

10th Madhya Pradesh Board

IMPORTANT

Earn 100

Why does the cord of an electric heater not glow while the heating element does?

Important Questions on Electricity

MEDIUM

10th Madhya Pradesh Board

IMPORTANT

SCIENCE TEXTBOOK FOR CLASS X>Chapter 12 - Electricity>QUESTIONS>Q 2

Compute the heat generated while transferring $96000 coulombs$ of charge in one hour through a potential difference of $50 V$ .

MEDIUM

10th Madhya Pradesh Board

IMPORTANT

SCIENCE TEXTBOOK FOR CLASS X>Chapter 12 - Electricity>QUESTIONS>Q 3

An electric iron of resistance $20 Ω$ takes a current of $5 A$ . Calculate the heat developed in $30 s$ .

EASY

10th Madhya Pradesh Board

IMPORTANT

SCIENCE TEXTBOOK FOR CLASS X>Chapter 12 - Electricity>QUESTIONS>Q 1

What determines the rate at which energy is delivered by a current?

MEDIUM

10th Madhya Pradesh Board

IMPORTANT

SCIENCE TEXTBOOK FOR CLASS X>Chapter 12 - Electricity>QUESTIONS>Q 2

An electric motor takes

5 A

from a

220 V

line. Determine the power of the motor and the energy consumed in

2 h

.

MEDIUM

10th Madhya Pradesh Board

IMPORTANT

SCIENCE TEXTBOOK FOR CLASS X>Chapter 12 - Electricity>EXERCISES>Q 1

A piece of wire of resistance

R

is cut into five equal parts. These parts are then connected in parallel. If the equivalent resistance of this combination is

R'

, then the ratio

\frac{R}{R'}

is –

EASY

10th Madhya Pradesh Board

IMPORTANT

SCIENCE TEXTBOOK FOR CLASS X>Chapter 12 - Electricity>EXERCISES>Q 2

Which of the following terms does not represent electrical power in a circuit?

EASY

10th Madhya Pradesh Board

IMPORTANT

SCIENCE TEXTBOOK FOR CLASS X>Chapter 12 - Electricity>EXERCISES>Q 3

An electric bulb is rated

220 V

and

100 W

. When it is operated on

110 V

, the power consumed will be –

MEDIUM

10th Madhya Pradesh Board

IMPORTANT

SCIENCE TEXTBOOK FOR CLASS X>Chapter 12 - Electricity>EXERCISES>Q 4

Two conducting wires of the same material and of equal lengths and equal diameters are first connected in series and then parallel in a circuit across the same potential difference. The ratio of heat produced in series and parallel combinations would be

Learn and Prepare for any exam you want !

|

|

|

|

|

|

|

|