1. Why a glass rod gets charged when rubbed with silk cloth
(A) It takes in protons
(B) its atoms are removed
(C) It removes electrons
(D) It gives positive charge
Answer: (C)
2. 122. The magnitude of current in AC and DC circuits can be
reduced by
(A) reactor
(B) capacitor
(C) inductor
(D) register
Ans: (D)
3. It becomes more difficult to remove
(A) An electron from the orbit
(B) First electron from orbit
(C) Second electron from orbit
(D) Third electron from orbit
Ans: (D)
4. When a branch of a parallel circuit is opened, what will be the
effect on the current?
(A) will decrease
(B) Increase
(C) decrease
(D) becomes zero
Answer: (C)
5. When more than one lamp is turned on in a lamp load, what will
be the effect on the total resistance
(A) increases
(B) decreases
(C) remains the same
(D) None of the above
Ans: (B)
6. 230v AC of two lamps 100w and 40w. If connected with supply in
series
Which of the following statements is correct?
(A) 100 watt lamp will glow more
(B) 40 watt lamp will glow more
(C) Both lamps will shine equally
(D) 40 W lamp will fuse
Ans: (B)
7. The resistance of 100 W, 220 V lamps will be
(A) 4.84 ohms
(B) 48.4 ohm
(C) 484 ohms
(D) 4840 ohm
Answer: (C)
8. D.C. In the case of
(A) The magnitude and the direction of current are constant
(B) The magnitude and direction of current changes over time
(C) the magnitude of the current changes over time
(D) the magnitude of the current remains constant
Answer: (A)
9. When electric current passes through a bucket filled with
water, a lot of bubbling is seen. This shows what is the type of supply
(A) A.C.
(B) D.C.
(C) Either of the above
(D) None of the above
Ans: (B)
10. Resistance of carbon filament lamps when supply voltage
increases.
(A) increases
(B) decreases
(C) remains the same
(D) None of the above
Ans: (B)
11. Which of the following quantities remain the same in all parts
of a series circuit?
(A) voltage
(B) current
(C) power
(D) resistance
Ans: (B)
12. A 40w bulb is connected in series with a room heater. If the
40w bulb is replaced with a 100w bulb now, the heater output will be
(A) decrease
(B) increase
(C) be equal
(D) the heater will burn
Ans: (B)
13. In an electric kettle, the water boils in 10 minutes, it is
necessary to boil the boiler in 15 minutes, what changes will have to be made
if the supply voltage is kept the same
(A) The length of the heating element should be reduced
(B) The length of the heating element should be increased
(C) Heating element length has no effect on heating on water
(D) None of the above
Answer: (A)
14. Electric filament of a bulb can work on which supply
(A) D.C. supply only
(B) A.C. supply only
(C) Battery supply only
(d) All of the above
Ans: (d)
15. What is the effect of increasing the applied voltage on the
resistance of tungsten lamps
(A) decreases
(B) increases
(C) remains the same
(D) None of the above
Ans: (B)
16. Electric current passing through the circuit is generated
(A) magnetic effect
(B) luminous effect
(C) Thermal effect
(D) Chemical effects
Answer: (C)
17. The resistance of a material always decreases if
(A) The temperature of the material decreases
(B) The temperature of the material increases
(C) The number of available free electrons increases
(D) None of the above is correct
Answer: (C)
18. If the efficiency of a machine should be reduced for more?
(A) input power
(B) losses
(C) True component of power
(D) kWh consumed
Ans: (B)
19. When electric current passes through a metallic conductor, its
temperature increases. this is due to
(A) collision between conduction electrons and atoms
(B) release of conduction electrons from parent atoms
(C) mutual collision between metal atoms
(D) Mutual collision between the conduction of electrons
Answer: (A)
20. If two bulbs are of 200 W and 500 W of 250 V, what will be
their resistance ratio?
(A) 4: 25
(B) 25: 4
(C) 2: 5
(D) 5: 2
Answer: (C)
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