A. magnetic effect
B. luminous effect
C. thermal effect
D. chemical effect
E. all above effects
With three resistances connected in parallel, if each dissipates 20 W the total power supplied by the voltage source equals_____________?
A. 10 W
B. 20 W
C. 40 W
D. 60 W
In a circuit a 33 Q resistor carries a current of 2 A. The voltage across the resistor is
A. 33 V
B. 66 v
C. 80 V
D. 132 V
When resistance element of a heater fuses and then we reconnect it after removing a portion of it, the power of the heater will___________?
A. decrease
B. increase
C. remain constant
D. none of the above
One newton meter is same as_____________?
A. one watt
B. one joule
C. five joules
D. one joule second
Switching of a lamp in house produces noise in the radio. This is because switching operation produces________?
A. arcs across separating contacts
B. mechanical noise of high intensity
C. both mechanical noise and arc between contacts
D. none of the above
Copper wire of certain length and resistance is drawn out to three times its length without change in volume, the new resistance of wire becomes__________?
A. 1/9 times
B. 3 times
C. 9 times
D. unchanged