Electricity

A wire of length /, made of material resistivity ρ is cut into two equal parts. The resistivity of the two parts are equal to
1. ρ
2. ρ/2
3. 2ρ
4. 4ρ
A battery of 10 volt carries 20,000 C of charge through a resistance of 20 Ω. The work done in 10 seconds is
1. 2 × 10³ joule
2. 2 × 10⁵joule
3. 2 × 10⁴ joule
4. 2 × 10² joule
A boy records that 4000 joule of work is required to transfer 10 coulomb of charge between two points of a resistor of 50 Ω. The current passing through it is
1. 2 A
2. 4 A
3. 8 A
4. 16 A
To get 2 Ω resistance using only 6 Ω resistors, the number of them required is
1. 2
2. 3
3. 4
4. 6
Two devices are connected between two points say A and B in parallel. The physical quantity that will remain the same between the two points is
1. Current
2. Voltage
3. resistance
4. None
The least resistance obtained by using 2 Ω, 4 Ω, 1 Ω and 100 Ω is
1. < 100 Ω
2. < 4 Ω
3. < 1 Ω
4. < 2 Ω
A current of 1 A is drawn by a filament of an electric bulb. Number of electrons passing through a cross section of the filament in 16 seconds would be roughly
1. 10²⁰
2. 10¹⁶
3. 10¹⁸
4. 10²³
What is the maximum resistance which can be made using five resistors each of 1/5 Ω?
1. 1/5 Ω
2. 10 Ω
3. 5 Ω
4. 1 Ω
What is the minimum resistance which can be made using five resistors each of 1/5 Ω?
1. 1/5 Ω
2. 1/25 Ω
3. 1/10 Ω
4. 25 Ω
The resistivity does not change if
1. the material is changed
2. the temperature is changed
3. the shape of the resistor is changed
4. both material and temperature are changed
In an electrical circuit three incandescent bulbs A, B and C of rating 40 W, 60 W and 100 W respectively are connected in parallel to an electric source. Which of the following is likely to happen regarding their brightness?
1. Brightness of all the bulbs will be the same
2. Brightness of bulb A will be the maximum
3. Brightness of bulb B will be more than that of A
4. Brightness of bulb C will be less than that of B
In an electrical circuit two resistors of 2 Ω and 4 Ω respectively are connected in series to a 6 V battery. The heat dissipated by the 4 Ω resistor in 5 s will be
1. 5 J
2. 10 J
3. 20 J
4. 30 J
Two resistors of resistance 2 Ω and 4 Ω when connected to a battery will have
1. same current flowing through them when connected in parallel
2. same current flowing through them when connected in series
3. same potential difference across them when connected in series
4. different p
Unit of electric power may also be expressed as
1. volt ampere
2. kilowatt hour
3. watt second
4. joule second
A fuse wire repeatedly gets burnt when used with a good heater. It is advised to use a fuse wire of
1. more length
2. less radius
3. less length
4. more radius
The resistivity does not change if
1. the material is changed
2. the temperature is changed
3. the shape of the resistor is changed
4. both material and temperature are changed
Electric potential is a
1. scalar quantity
2. vector quantity
3. neither scalar nor vector
4. sometimes scalar and sometimes vector
Coulomb is the SI unit of
1. charge
2. current
3. potential difference
4. resistance
When electric current is passed, electrons move from
1. high potential to low potential.
2. low potential to high potential.
3. in the direction of the current.
4. against the direction of the current
The heating element of an electric iron is made up of
1. copper
2. nichrome
3. aluminium
4. iron
The electrical resistance of insulators is
1. high
2. low
3. Zero
4. infinitely high
Electrical resistivity of any given metallic wire depends upon
1. its thickness
2. its shape
3. nature of the material
4. its length
Electric power is inversely proportional to
1. resistance
2. voltage
3. current
4. temperature
What is the commercial unit of electrical energy?
1. Joules
2. kilojoules
3. kilowatt-hour
4. watt-hour
An electric bulb is connected to a 220V generator. The current is 0.50 A. What is the power of the bulb?
1. 440W
2. 110W
3. 55W
4. 0.0023W

Electricity

Quiz