The device used for measuring potential difference is known as
voltmeter
galvanometer
voltameter
potentiometer
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
1kWh =
3.6 x 103J
3.6 x 106J
3.6 x 109J
none of these
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 potential difference between the terminals of an electric iron is 240 V and the current is 5.0 A. What is the resistance of the electric iron?
48 Ω
4.8 Ω
0.48 Ω
480 Ω
The reciprocal of a resistance of a conductor is
conductance
capacitance
conductivity
impedance
An electric fuse works on the :
chemical effect of current
magnetic effect of current
lighting effect of current
heating effect of current
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
A wire whose resistance is 90 Ω is cut into 3 pieces of equal lengths which are then arranged in parallel.Calculate the resistance of the combination.
10 Ω
1/10 Ω
30Ω
1/30Ω
The work done in moving a unit charge across two points in an electric circuit is a measure of :
current
potential difference
resistance
power
