Current Electricity Model Quiz free test2

Thank you very much for taking test

Test your caliber

1. If a parallel circuit is opened in the main line, the current _____.
increases in the branch of the lowest resistance	increases in each branch
is zero in all branches	is zero in the highest resistive branch

2. If a wire conductor of 0.2 ohm resistance is doubled in length, its resistance becomes
0.4 ohm	0.6 ohm
0.8 ohm	1.0 ohm

3. Three 60 W bulbs are in parallel across the 60 V power line. If one bulb burns open _____.
there will be heavy current in the main line	rest of the two bulbs will not light
all three bulbs will light	the other two bulbs will light

4. The four bulbs of 40 W each are connected in series wifti a battery across them, which of the following statement is true ?
The current through each bulb in same	The voltage across each bulb is not same
The power dissipation in each bulb is not same	None of the above

5. Two resistances R1 and R2 are connected in series across the voltage source where R2>R1. The largest drop will be across
R2	R1
either R1 or R2	none of them

6. What will be energy used by the battery if the battery has to drive 6.28 x 1018 electrons with potential difference of 20 V across the terminal ?
5 joules	10 joules
15 joules	20 joules

7. A closed switch has a resistance of _____.
zero	about 50 ohms
about 500 ohms	infinity

8. The hot resistance of the bulb's filament is higher than its cold resistance because the temperature co-efficient of the filament is _____.
zero	negative
positive	about 2 ohms per degree

9. Heat in a conductor is produced on the passage of electric current due to _____.
reactance	capacitance
impedance	resistance

10. The insulation on a current carrying conductor is provided _______.
to prevent leakage of current	to prevent shock
both of above factors	none of above factors

11. The thickness of insulation provided on the conductor depends on ______.
the magnitude of voltage on the con-ductor	the magnitude of current flowing through it
both (a) and (b)	none of the above

12. Which of the following quantities remain the same in all parts of a series circuit ?
Voltage	Current
Power	Resistance

13. A 40 W bulb is connected in series with a room heater. If now 40 W bulb is replaced by 100 W bulb, the heater output will ______.
decrease	increase
remain same	heater will burn out

14. In an electric kettle water boils in 10m minutes. It is required to boil the boiler in 15 minutes, using same supply mains
length of heating element should be decreased	length of heating element should be increased
length of heating element has no effect on heating if water	none of the above

15. An electric filament bulb can be worked from ______.
D.C. supply only	A.C. supply only
Battery supply only	All above

16. Resistance of a tungsten lamp as applied voltage increases
decreases	increases
remains same	none of the above

17. Electric current passing through the circuit produces _______.
magnetic effect	luminous effect
thermal effect	chemical effect

18. Resistance of a material always decreases if ______.
temperature of material is decreased	temperature of material is increased
number of free electrons available become more	none of the above is correct

19. If the efficiency of a machine is to be high, what should be low ?
Input power	Losses
True component of power	kWh consumed

20. When electric current passes through a metallic conductor, its temperature rises. This is due to ______.
collisions between conduction electrons and atoms	the release of conduction electrons from parent atoms
mutual collisions between metal atoms	mutual collisions between conducting electrons