Advertisements
Advertisements
प्रश्न
Why is heating element wound on a long porcelain rod in a room heater.
Advertisements
उत्तर
This reduces the area over which element of the heater is spread. As heat is produced over smaller area, therefore temperature of its element rises to about 1000°C.
संबंधित प्रश्न
Define watt. Write down an equation linking watts, volts and amperes.
Which of the following is likely to be the correct wattage for an electric iron used in our homes?
(a) 60 W
(b) 250 W
(c) 850 W
(d) 2000 W
1Kwh =`( 1 "volt "xx 1 am pere xx.............)/1000`
A current of 0.2 A flows through a wire whose ends are at a potential difference of 15 V.
calculate:
(i) the resistance of the wire and
(ii) the heat energy produced in 1 minute.
The diagram shows a coil connected to a center zero galvanometerG . The galvanometer shows a deflect ion to the right when the north pole N of a powerful magnet is moved to the right as shown .
(i) Explain, why the defelct ion occurs in the galvanometer.
(ii ) State whether th e current in the coil is cl ockwise or anticl ockwise
when viewed from the end P.
(iii ) State th e observation in G when the coil is moved away from north
pole N of the magnet keeping the magnet stationary.
(iv)State the observation in G when both the coil and the magnet are
moved to right at th e same speed .
Two resistors A and B of 4 Ω and 6 Ω, respectively are connected in parallel. The combination is connected across a 6 volt battery of negligible resistance. Calculate the power dissipated in each resistor.
An electric heater is rated 220 V, 550 W. Calculate the electrical energy consumed in 3 hours?
You are required to connect a bulb, a fan and a socket outlet to the mains in one set A and an air-conditioner and a refrigerator to the mains in other set B. Will you recommend the wire of same thickness and same insulation in both? explain your answer.
The unit of e.m.f. of a cell is ____________.
1 kWh = ____________
