Advertisements
Advertisements
प्रश्न
An electric iron of resistance 20 Ω takes a current of 5 A. Calculate the heat developed in 30 s.
Advertisements
उत्तर
The amount of heat (H) produced is given by the joule’s law of heating as H = Vlt
Where,
Current, I = 5 A
Time, t = 30s
Voltage, V = Current × Resistance
= 5 × 20
= 100 V
H = 100 × 5 × 30
= 1.5 × 104 J.
Therefore, the amount of heat developed in the electric iron is 1.5 × 104 J.
APPEARS IN
संबंधित प्रश्न
Write Joule's law of heating.
An electric heater is connected to the 230 V mains supply. A current of 8 A flows through the heater.
(b) How much energy is transferred to the heater each second?
Why is a series arrangement not used for connecting domestic electrical appliances in a circuit?
Write down the formula for the heat produced when a current I is passed through a resistor R for time t.
A heating coil has a resistance of 200 Ω. At what rate will heat be produced in it when a current of 2.5 A flows through it?
The heat produced in a wire of resistance 'x' when a current 'y' flows through it in time 'z' is given by:
(a) x2 × y × z
(b) x × z × y2
(c) y × z2 × x
(d) y × z × x
Identify the figure and give its use.
Heat energy is being produced in a resistance in a circuit at the rate of 100 W. The current of 3 A is flowing in the circuit. What must be the value of the resistance?
Answer the following question:
what is the heating effect of the electric current? state any four applications of it?
The ‘live’ and the ‘neutral’ wires have potential difference of _______.
A coil of an alloy _______ is used in electric heater cooker as a resistor.
What is overloading?
Name any two appliances which works on the phenomenon of heating effect of electric current.
When does overloading occur?
Heating effect of current is called ______
Why is parallel arrangement used in domestic wiring?
Your teacher has shown you the following activity.
Activity: Teacher has wound a long insulated piece of wire around an iron nail in the form of a coil. Free ends of the wire are connected to a cell through a switch as shown in the following figure. The current is switched on and some pins are placed near the ends of the nail.
Write down any three questions that come to your mind about this activity.
A trip switch is a ______ safety device.
Define the following:
Electrolyte
If 220 V potential difference is applied across an electric bulb, a current of 0.45 A flows in the bulb. What must be the power of the bulb?
