Advertisements
Advertisements
प्रश्न
An electric current is passed through a metallic wire. The wire gets heated up. Give the reason. Is it possible to melt the wire by passing a heavy current?
उत्तर
The metallic wire gets heated up on passing an electric current through it due to collisions of free electrons and energy is transferred to the positive ions which begin to vibrate more violently, causing to produce heat. It is possible to melt the wire by passing a heavy current. The wire will melt when its temperature due to heating reaches its melting point.
APPEARS IN
संबंधित प्रश्न
What is consumed using different electrical appliances, for which electricity bills are paid?
If a bulb of 60W is connected across a source of 220V, find the current drawn by it.
What is the SI unit of (i) electric energy, and (ii) electric power?
How many joules of electrical energy are transferred per second by a 6 V; 0.5 A lamp?
(a) 30 J/s
(b) 12 J/s
(c) 0.83 J/s
(d) 3 J/s
1kWh = …….. J
Water in an electric kettle connected to a 220 V supply took 5 minutes to reach its boiling point. How long would it have taken if the supply voltage had fallen to 200 V?
The coil of an electric bulb takes 40 watts to start glowing. If more than 40 W are supplied, 60% of the extra power is converted into light and the remaining into heat. The bulb consumes 100 W at 220 V. Find the percentage drop in the light intensity at a point if the supply voltage changes from 220 V to 200 V.
State the position of heating element with respect to principal focus of concave reflector and give reason for choosing this position.
An electric bulb is rated as 100W – 250V. What information does it convey? Calculate the current through the filament of the bulb.
The resistance of filament of an electric heater is 500 Ω It is operated at 200V for 1 hour daily. Calculate the current drawn by the heater and the energy consumed in kWh, by the heater in a month of 30 days.
