20 questions
Ohm's law ststes that the ratio V/I is constant for
i. steel
ii. An electrolyte
iii. silver
iv. diode
Which of th above are correct?
i and ii only
i and iii only
iii and iv only
i, ii, iii, iv
The quantity of electricity is measured in the unit of
Ampere
the volt
the coulomb
the electromotive force
The energy needed to move a unit positive charge around a complete electric circuit is called the
electromotive force
electric potential difference
electrical energy
kinetic energy
A current of 180 mA passes through a conductor for 5 minutes
54 C
0.9C
0.036 C
0.0009 C
60 mC of electricity passes through a conductor for 2 minutes. The current through the conductor is
7.2 A
120 mA
30 mA
0.5 mA
Wire X has twice the diameter and twice the length of wire Y made of thesame material. The ratio of the ressistance of X to Y is
1:4
4:1
1:2
1:1
Which of the given is the SI Unit of Electric Current?
Ohm
Ampere
Volt
Faraday
The hindrance presented by material of conductor to the smooth passing of electric current is known as:
Resistance
Conductance
inductance
capacitance
The rate of flow of an electric charge is known as
electric potential
conductance
current
pd
The instrument used for measuring electric current is
Ammeter
Voltmeter
Potentiometer
rheostart
A cell of emf 2V and internal resistance 0.5 Ohms delivers a current of 0.4 A to an external resistance R. The value of R is
1.2 Ohms
1.5 Ohms
4 ohms
4.5 Ohms
The efficiency of a cell of internal resistance 0.5 Ohms which supplies current to a 2 Ohms resistor is
20%
25%
75%
80%
Three cells each of emf 1.1 V and internal resistance 2 Ohms are connected in parallel across a 3 Ohms resistor. The current in the resistor is ------
0.20A
0.24A
0.30A
0.40A
Which of the following combinations of the three resistors 4 Ohms, 6 Ohms, and 12 Ohms will give an equivalent of 2 Ohms?
All three resistors in series
A parallel combination of the 4 Ohms and 6 Ohms resistors in series with the 12 Ohms rsistor.
A parallel combination of the 6 ohm and the 12 Ohm resistor in series with the 4 ohm resistor
All three resistors in parallel
An electric kettle connected to a 200 V mains generates 3 00000 J of heat energy in 2.5 minutes. The resistance of the heating element of the kettle is
2 Ohm
4 Ohm
8 Ohm
20 Ohm
The resistance connected to a 12 V battery draws a current of 2 A. The energy dissipated in the resistor in 5 minutes is
3600 J
6000 J
7200 J
14, 400 J
Two resistors Ra and Rb are connected in parallel. If Ra > Rb, the combined resistance is
Less than Ra
greater than Rb
Ra + Rb
Greater than Ra but less than Rb
A man has three 100 W bulbs, five 60 W bulbs and five 40 W light bulbs in his apartment. If he turns all the light on for 5 hours daily and the cost of electricity is #1.20 per unit, his bill for 30 days is
#4.80
#12
#28.80
#144
Which of the following appliances draws the highest current ?
1.1KW, 220V
440KW, 110V
100 W, 200V
40 W, 6 V
Heat is developed in a wire through which a current is passed. On which of the following does the heat developed depend?
1. The time for which the current passes
2. The square of the electric current
3. The resistance of the wire
4. The melting point of the wire
1 and 2 only
1, 2, and 3 only
1, 2, and 4 only
2 and 3 only