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Worksheets7th Ch-14 Electric Current and its effect
Total questions: 20
Worksheet time: 10mins
Connection of more than one device/ appliance to a single socket is called-
Overloading
Short circuit
Both
A common household device, that do not use an electromagnet in its working, is-
The electric bell
Geyser
Telephone
Loud speaker
The heating coils/elements of different electrical appliances are usually made from ________ or ________ wires.
1. Copper 2. Aluminum 3. Nichrome 4. Tungsten
1 & 2
1 & 4
2 & 4
3 & 4
When electric current flows through the metal filament of the bulb it gets heated to very high temperature and becomes______ hot and start emitting _______.
White, light
Red, light
White, heat
Red, heat
Which one of the following is the most energy efficient
LED
Incandescent bulb
CFL
The heating effect of an electric current is used in
Hair dryer
A fan
A computer
A combination of two or more cells is called
A button cell
A battery
An electric cell
Truck battery
Substances through which electric charges flow easily are called
Wire
Metal
Conductors
Insulators
Which is true about a cell?
Longer line represent-Positive terminal and Shorter line represents-Negative Terminal
Longer line represent-Negative terminal and Shorter line represents-Positive Terminal
Both line represent-Positive Terminal
Both line represents-Negative Terminal
Full form of-CFL
Compact Flood Light
Common Full Light
Compact Fluorescent Lamp
Compact Flood Lamp
Three bulbs A, B, C are connected in a circuit as shown in Figure, When the switch is ‘ON'
bulb C will glow first.
bulb B and C will glow simulaneously and bulb A will glow after some time.
the bulbs will glow in the order A, B and C
all the bulbs A,B and C will glow at the same time
WHo discovered the magnetic effect of current?
Galileo Galilei
Newton
Marconi
H C Oersted
When electricity flows through heating coil it becomes ________ hot and gives out _______ energy, which is to put in practical use.
Red, heat
White, heat
Red, light
White, light
1.An electric current can produce
heating effect only.
chemical effect only.
magnetic effect only.
chemical, heating, and magnetic effects.
Can we magnetise an iron object with electromagnet
Yes
No
What is the symbol for a cell?
Identify closed circuit.
A _________ is a safety device which prevents damages to electrical circuits and possible fires.
Battery
Fuse
Wire
The amount of heat produced in a wire depends on
Material
Length
Thickness
All of these
Which mark is necessary on electric appliances?
AGMARK
ISI
FICCI
KSK
