A 100 W,220 V bulb is connected across 110 V supply.The actual power consumed by the bulb will be
25 W
50 W
100 W
200 W
The resistance of a wire of length 300 m and cross section area 1.0 mm2 made of material of resistivity 1.0 x 10-7 Ωm is :
2 Ω
4 Ω
20 Ω
30 Ω
Which unit could be used to measure current?
Ampere
Volt
Coulomb
Watt
What is the order of magnitude of electric resistance of the human body (dry)?
102 ohm
104 ohm
106 ohm
108 ohm
Assertion (A) : The temperature of a metal wire rises when an electric current is passed through it.
Reason (R) : Collision of metal atoms with each other releases heat energy.
Both A and R are true and R is the correct explanation of A
Both A and R are true but R is not a correct explanation of A
A is true but R is false
A is false but R is true
The elements of electrical heating devices are usually made of :
tungsten
bronze
nichrome
argon
The heat produced by passing an electric current through a fixed resistor is proportional to the square of :
magnitude of resistance of the resistor
temperature of the resistor
magnitude of current
time for which current is passed
A current of 0.5 A is drawn by a filament of an electric bulb for 10 minutes. Calculate the amount of electric charge that flows through the circuit.
200 C
300 C
400 C
100 C
When an electric lamp is connected to 12 V battery,it draws a current of 0.5 A.The power of the lamp is
0.5 W
12 W
6 W
24W
The substance having infinitely high electrical resistance is called :
conductor
resistor
superconductor
insulator