Advertisements
Advertisements
प्रश्न
Three 2 V cells are connected in series and used as a battery in a circuit.
What is the p.d. at the terminals of the battery?
Advertisements
उत्तर
The potential difference across each cell is 2 V. So, the potential difference at the terminals of the battery is 3 x 2 V = 6 V.
APPEARS IN
संबंधित प्रश्न
Calculate the number of electrons constituting one coulomb of charge.
Why are metals good conductors of electricity whereas glass is a bad conductor of electricity? Give reason?
Consider the circuit given below when A, B and C are three identical light bulbs of constant resistance.
(a) List the bulbs in order of increasing brightness.
(b) If C burns out, what will be the brightness of A now compared with before?
(c) If B burns out instead, what will be the brightness of A and C compared with before?
Name two effects produced by electric current.
The following circuit diagram shows three resistors 2 Ω, 4 Ω and R Ω connected to a battery of e.m.f 2V and internal resistance 3 Ω. If the main current of 0.25 A flows through the circuit, find:
- the p.d. across the 4 Ω resistors,
- the p.d. across the internal resistance of the cell,
- the p.d. across the R Ω or 2 Ω resistors, and
- the value of R.

An electric current flowing in a wire creates ______ around the wire.
A current of 0.3 A is flowing through a branch of 6 Ω resistors in a junction as shown in fig. . Calculate the
(a) P.d. across the junction XY,
(b) Current flowing through 9Ω and 24Ω
( c) P.d. across 24 Ω resistor, and
( d) e.m.f. of the cell.

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.
Fig. shows a 3 pin plug with the cover removed. The electric cable
connected to the plug contains 3 wires with colour coded insulation namely brown, blue and green.

- Identify each of the colour coded wires by stating to which of the
terminals A, B or C in the diagram they should be connected. - Identify the terminal through which no current passes in normal
circumstances. - What is the purpose of the earthed wire connected to an electric
appliance like an electric heater? Describe how it works.
Tick (✓) the correct choice among the following :
There are 500 turns and 2000 turns in the primary and secondary coil of a
transformer respectively. If th e output voltage is 1000 V, how large is the
input voltage?
State the S.I. units of electrical power.
A bulb marked 12 V, 24 W operates on a 12 V battery for 20 minutes. Calculate:
- The current flowing through it, and
- The energy consumed.
Three heaters each rated 250 W, 100 V are connected in parallel to a 100 V supply. Calculate :
The total current taken from the supply
Two electric bulbs rated 100 W; 220 V and 60 W; 220 V are connected in parallel to electric mains of 220 V. Find the current drawn by the bulbs from the mains.
Kilowatt hour is the unit of
Conventionally, the direction of the current is taken as:
Problems for practice:
If 3A current flows through a circuit, then convert the current in terms of a milliampere.
