Practice Test: Question Set - 07
1. Voltage dependent resistors are used
- (A) For inductive circuits
- (B) To suppress surges
- (C) As heating elements
- (D) As current stabilizers
2. If I, R and t are the current, resistance and time respectively, then according to Joule's law heat produced will be proportional to
- (A) I2Rt
- (B) I2Rf
- (C) I2R2t
- (D) I2R2t2
3. Which one of the following does not have negative temperature coefficient?
- (A) Aluminium
- (B) Paper
- (C) Rubber
- (D) Mica
4. Electric pressure is also called
- (A) Resistance
- (B) Power
- (C) Voltage
- (D) Energy
5. With rise in temperature the resistance of semiconductors
- (A) Decreases
- (B) Increases
- (C) First increases and then decreases
- (D) Remains constant
6. Ohm's law is not applicable to
- (A) Vacuum tubes
- (B) Carbon resistors
- (C) High voltage circuits
- (D) Circuits with low current densities
7. The four bulbs of 40 W each are connected in series swift a battery across them, which of the following statement is true?
- (A) The current through each bulb in same
- (B) The voltage across each bulb is not same
- (C) The power dissipation in each bulb is not same
- (D) None of the above
8. If the efficiency of a machine is to be high, what should be low?
- (A) Input power
- (B) Losses
- (C) True component of power
- (D) kWh consumed
9. Resistance of 220 V, 100 W lamp will be
- (A) 4.84 Q
- (B) 48.4 Q
- (C) 484 ft
- (D) 4840 Q
10. Three 6 ohm resistors are connected to form a triangle. What is the resistance between any two corners?
- (A) 3/2 Q
- (B) 6 Q
- (C) 4 Q
- (D) 8/3 Q