Advertisements
Advertisements
प्रश्न
State three factors on which the heat produced by an electric current depends. How does it depend on these factors?
Advertisements
उत्तर
The heat produced by an electric current depends on the square of the current, the resistance of the device and the time for which the current is passed through the device, i.e.:
H = I2Rt
APPEARS IN
संबंधित प्रश्न
An electric circuit consisting of a 0.5 m long nichrome wire XY, an ammeter, a voltmeter, four cells of 1.5 V each and a plug key was set up.
(i) Draw a diagram of this electric circuit to study the relation between the potential difference maintained between the points 'X' and 'Y' and the electric current flowing through XY.
Give three reasons why different electrical appliances in a domestic circuit are connected in parallel.
In which of the following cases more electrical energy is consumed per hour?
(i) A current of 1 ampere passed through a resistance of 300 ohms.
(ii) A current of 2 amperes passed through a resistance of 100 ohms.
Three resistors of 6.0 𝛀, 2.0𝛀 and 4.0𝛀 are joined to an ammeter A and a cell of e.m.f. 6.0 V as
shown in fig 8.52 Calculate:
(a) the effective resistance of the circuit and
(b) the reading of ammeter.
A 720 W heater operates from a 220 V line voltage. Calculate:
(a) The electrical energy consumed by the heater in 3 h.
(b) The cost of electrical energy consumption at the rate of 60 paise per kWh.
Tick(✓) the correct choice in the following:
Which of the following quantities has the same value for all electrical
appliances connected to the ring main circuit in a house?
Define the following:
Semiconductors
Find the effective resistance in the following circuit diagrams (Fig.):
The circuit diagram (Fig.) shows a battery of e.m.f. 6 volts and internal
resistance of 0.8 Ω oonnected in series. Find the
(a) Current reoorded by the ammeter,
(b) P.d. across the terminals of the resistor B,
( c) Current passing through each of the resistors B, C and D, and
( d) P.d. across the terminals of the battery.
What would be the danger involved in replacing a blown fuse with the one which would carry a large current?
A 3 pin mains plug is fitted to the lead for a 1 kW electric kettle to be used on a 250 V A.C. supply. Which of the following statements is NOT correct?
(a) A 13 A fuse is the most appropriate value to use.
(b) The brown wire should be connected to the live side of the mains.
A bulb is connected to a battery of p.d. 4 V and internal resistance 2.5 Ω . A steady current of 0.5 A flows through the circuit. Calculate:
The energy dissipated in the bulb in 10 minutes.
Explain, why the potential difference across the terminals of a cell is more when the cell is not in use than it is when the cell is being used.
