Advertisements
Advertisements
प्रश्न
One coulomb charge is equivalent to the charge contained in:
(a) 2.6 × 1019 electrons
(b) 6.2 × 1019 electrons
(c) 2.65 × 1018 electrons
(d) 6.25 × 1018 electrons
Advertisements
उत्तर
6.25 × 1018 electrons
Since the charge of an electron is `1.6xx10^(-19)C` 6.25 × 1018 electrons taken together constitute (6.25 × 1018 × 1.6 × 10−19 C) or 1 coulomb of charge.
APPEARS IN
संबंधित प्रश्न
Draw the electrical symbols of the following components and state its use:
Rheostat (variable resistance)
If 20 C of charge pass a point in a circuit in 1 s, what current is flowing?
Why should the resistance of:
an ammeter be very small?
The p.d. across a 3 Ω resistor is 6 V. The current flowing in the resistor will be:
(a) `1/2A`
(b) 1 A
(c) 2 A
(d) 6 A
Which type of circuit, series or parallel, is preferred while connecting a large number of bulbs:
(a) for decorating a hotel building from outside?
An electrician has wired a house in such a way that if a lamp gets fused in one room of the house, all the lamps in other rooms of the house stop working. What is the defect in the wiring?
State the S.I. unit of current.
Define the following:
Semiconductors
An electric kettle has a heating element which is rated at 2 kW when connected to a 250 V electric supply. Calculate the
(a) Current which flows in the element when it is connected to a 250 V supply,
(b) Resistance of the filament,
(c) Heat produced in 1 minute by the element,
(d) Cost of running the kettle for 10 minutes a day for 30 days of the month, at the rate of Rs. 3.00 per unit.
The circuit diagram in fig shows two coils of an insulated copper wire wound on a cardboard tube. G is a center zero galvanometer.
(a) Describe what will happen when th e swi tch K is cl osed for severa l
seconds and then opened again .
(b) What will be the effect of repeating the experiment with an iron placed in the tube?
State the S.I. units of electrical power.
An electric bulb is rated at 220 V, 100 W.
- What is its resistance?
- What safe current can be passed through it?
A bulb of 40 W is used for 12.5 h each day for 30 days. Calculate the electrical energy consumed.
A geyser is rated 1500 W, 250 V. This geyser is connected to 250 V mains. Calculate:
- The current drawn,
- The energy consumed in 50 hours, and
- The cost of energy consumed at ₹ 4.20 per kWh.
Answer the following question.
An electric lamp of resistance 20 Ω and a conductor of resistance 4 0 are connected to a 6 V battery as shown in the circuit. Calculate: 
(a) the total resistance of the circuit,
(b) the current through the circuit,
(c) the potential difference across the (i) electric lamp and (ii) conductor, and
(d) power of the lamp.
Which part of an electrical appliance is earthed?
MCB is used to protect household electrical appliances.
Problems for practice:
If 5A current flows through a circuit, then convert the current in terms of microampere?
