SCIENCE AND TECHNOLOGY – Math-Science Dears

SCIENCE AND TECHNOLOGY – Chapter 3

Electricity

1 / 15

In the given figure, the resistors

6 Ω, 3 Ω and 9 Ω are in series

9 Ω and 6 Ω are in parallel and the combination is in series with 3 Ω

3 Ω, 6 Ω and 9 Ω are in parallel

3 Ω and 6 Ω are in parallel and the combination is in series with 9 Ω

2 / 15

You are given four ammeters A, B, C and D having least counts mentioned below:
(I) Ammeter A with least count 0.25 A
(II) Ammeter B with least count 0.5 A
(III) Ammeter C with least count 0.05 A
(IV) Ammeter D with least count 0.1 A
Which of the ammeters would you prefer for doing an experiment to determine the equivalent resistance of two resistances most accurately, when connected in parallel?

Ammeter A

Ammeter B

Ammeter C

Ammeter D

3 / 15

If the current flowing through a fixed resistor is halved, the heat produced in it will become:

One-fourth

One-half

Double

Four times

4 / 15

At a given time, a house is supplied with 100 A at 220 V. How many 75 W, 220 V light bulbs could be switched on in the house at the same time (if they are all connected in parallel)?

193

293

393

5 / 15

Two electric bulbs have resistances in the ratio 1:2. If they are joined in series, the energy consumed in them is in the ratio.

2:1

1:2

4:1

1:1

6 / 15

When a current ‘I’ flows through a resistance ‘R’ for time ‘t’ the electrical energy spent is given by

IRt

I²Rt

IR²t

I²R/t

7 / 15

Two appliances of rating 200 watt-250 volts and 100 watt-250 volts are joined in series to a 250 volts supply. Total power consumed in the circuit is

46 watt

67 watt

10 watt

30 watt

8 / 15

A wire of resistance R1 is cut into five equal pieces. These five pieces of wire are then connected in parallel. If the resultant resistance of this combination be R2, then the ratio R1/ R2 is:

1/25

1/5

9 / 15

V1, V2 and V3 are the potential differences across the 1Ω, 2Ω and 3Ω resistors in the following diagram, and the current is 5A.

Which of the following shows the correct values of V1, V2 and V3 measured in volts?

V1 =1, V2 = 2 and V3 = 3

V1 =5, V2 = 10 and V3 = 15

V1 =5, V2 = 2.5 and V3 = 1.6

V1 =4, V2 = 3 and V3 = 2

10 / 15

The potential difference across the 3 Ω resistor in the following diagram is:

1/9 V

1/2 V

11 / 15

If in the given arrangement, the three resistors are to be replaced by a single resistor. What will be the value of this resistor?

4Ω

6Ω

9Ω

18Ω

12 / 15

Keeping the potential difference constant, the resistance of the circuit is halved. The current will become:

One-fourth

Four times

Half

Double

13 / 15

When a 4 Ω resistor is connected across the terminals of a 2 V battery, the number of coulombs passing through the resistor per second is:

0.5

14 / 15

An electrical appliance has a resistance of 25 Ω. When this electrical appliance is connected to a 230 V supply line, the current passing through it will be:

0.92 A

2.9 A

9.2 A

92 A

15 / 15

What is the amount of current flowing through an electric press, if the amount of charge passing through a conductor in 10 minutes is 300 C?

30 A

0.3 A

0.5 A

5 A

Your score is