Advertisements
Advertisements
प्रश्न
Why should the resistance of:
an ammeter be very small?
Advertisements
उत्तर
An ammeter should have a very low resistance so that it will not change the value of the current flowing in the circuit.
APPEARS IN
संबंधित प्रश्न
Compare how an ammeter and a voltmeter are connected in a circuit.
Which statement/statement is/are correct?
1. An ammeter is connected in series in a circuit and a voltmeter is connected in parallel.
2. An ammeter has a high resistance.
3. A voltmeter has a low resistance.
(a) 1, 2, 3
(b) 1, 2
(c) 2, 3
(d) 1
A student made an electric circuit shown here to measure the current through two lamps.
Are the lamps in series or parallel?
(a) Are the lamps in series or parallel?
(b) The student has made a mistake in this circuit. What is the mistake?
(c) Draw a circuit diagram to show the correct way to connect the circuit. Use the proper circuit symbols in your diagram.

Which type of circuit, series or parallel, is preferred while connecting a large number of bulbs:
(b) for lighting inside the rooms of the hotel?
Which is the better way to connect lights and other electrical appliances in domestic wiring: series circuits or parallel circuits? why?
Christmas tree lamps are usually wired in series. What happens if one lamps breaks?
A wire of uniform thickness with a resistance of 27Ω is cut into three equal pieces and they are joined in parallel. Find the equivalent resistance of the parallel combination.
Calculate the equivalent resistance between A and B in the adjacent diagram.

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.

Draw a schematic diagram of an electric circuit consisting of a battery of two cells each of 1.5 V, 5 Ω, 10 Ω and 15 Ω resistors and a plug key, all connected in series.
Distinguish between an open and a closed circuit.
Two resistors P and Q of the same material and length but of different thickness are connected in parallel to a battery. The cross- sectional area of P is twice that of Q. What is the ratio of
(a) The resistance of P to the resistance of Q?
(b) The current in P to the current in Q?
In a house there are 6 bulbs of 100 W each used for 4 hours a day, 4 bulbs of 60 W each used for 8 hours a day, an immersion heater of 2.5 kW used for 1 hour per day, and an electric iron of 800 W used for 2 hours per day. Calculate the cost of monthly electric bill for the month of April at the rate of 80 p per unit.
State whether the current is a scalar or vector?
Answer the following question.
What is the function of a galvanometer in a circuit?
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.
Conventionally, the direction of the current is taken as:
1020 electrons, each having a charge of 1.6 x 10-19 C, flows in a circuit V is 0.1s. What is the current in ampere?
