Time Left: 600 sec

1. The filament of electric bulb is made of –

A. Copper
B. Aluminium
C. Tungsten
D. Iron

2. Tungsten has a melting point of –

A. 2000°C
B. 2500°C
C. 3000°C
D. 3380°C

3. Bulbs are filled with –

A. Oxygen and nitrogen
B. Hydrogen and helium
C. Argon and nitrogen
D. Carbon dioxide

4. A fuse works on the principle of –

A. Heating effect of current
B. Magnetic effect of current
C. Chemical effect of current
D. Induction

5. The commercial unit of electrical energy is –

A. Watt
B. Joule
C. Kilowatt hour
D. Calorie

7. The power consumed by a device is given by –

A. P = VI
B. P = I²R
C. P = V²/R
D. All of these

8. SI unit of electric power is –

A. Joule
B. Watt
C. Coulomb
D. Ohm

9. 1 watt is equal to –

A. 1 J/s
B. 1 V × 1 A
C. Both A and B
D. 1 C/s

11. An electric iron requires a fuse of –

A. 1 A
B. 2 A
C. 5 A
D. 10 A

12. In a series connection of bulbs, if one bulb fuses –

A. All glow
B. Rest glow with less brightness
C. Rest do not glow
D. Brightness increases

13. Current through a conductor decreases when –

A. Length is reduced
B. Area is increased
C. Resistance increases
D. Voltage increases

14. Resistance of alloys is –

A. Lower than metals
B. Same as metals
C. Higher than constituent metals
D. Zero

15. Copper and aluminium are used for transmission lines because –

A. They are cheap
B. They are good insulators
C. They have low resistivity
D. They have high resistivity