Electricity – CBSE Class 10
1. A conductor is a material that
A) Allows electric current to flow easily
B) Does not allow current
C) Blocks light
D) Absorbs heat
Answer: Allows electric current to flow easily
2. Materials which allow current to flow are called
A) Conductors
B) Insulators
C) Semiconductors
D) Superconductors
Answer: Conductors
3. Examples of good conductors are
A) Copper and Aluminium
B) Wood and Rubber
C) Plastic and Glass
D) Air and Water
Answer: Copper and Aluminium
4. Insulators are materials that
A) Do not allow electric current to pass
B) Allow current to flow
C) Conduct electricity at high temperature
D) None
Answer: Do not allow electric current to pass
5. Examples of insulators are
A) Rubber, Plastic, Glass
B) Copper, Aluminium
C) Iron and Steel
D) Water
Answer: Rubber, Plastic, Glass
6. Fleming’s Left-Hand Rule is used to find
A) Direction of force on current-carrying conductor in magnetic field
B) Direction of current
C) Voltage
D) Resistance
Answer: Direction of force on current-carrying conductor in magnetic field
7. In Fleming’s Left-Hand Rule, the thumb represents
A) Direction of motion/force
B) Magnetic field
C) Current
D) Voltage
Answer: Direction of motion/force
8. In Fleming’s Left-Hand Rule, the forefinger represents
A) Magnetic field
B) Current
C) Force
D) Voltage
Answer: Magnetic field
9. In Fleming’s Left-Hand Rule, the middle finger represents
A) Direction of current
B) Force
C) Voltage
D) Magnetic field
Answer: Direction of current
Electricity – CBSE Class 10
10. Direct current (DC) is
A) Electric current flowing in one direction only
B) Alternating current
C) Current varying sinusoidally
D) Zero
Answer: Electric current flowing in one direction only
11. Source of DC includes
A) Battery, Cells
B) Electric generators
C) Transformer
D) Solar panels only
Answer: Battery, Cells
12. Alternating current (AC) is
A) Electric current that changes direction periodically
B) Current in one direction
C) Constant voltage
D) None
Answer: Electric current that changes direction periodically
13. Frequency of AC in India is
A) 50 Hz
B) 60 Hz
C) 25 Hz
D) 100 Hz
Answer: 50 Hz
14. Advantage of AC over DC is
A) It can be transmitted over long distances with less loss
B) It cannot be transmitted
C) AC is more dangerous
D) None
Answer: It can be transmitted over long distances with less loss
15. DC is used in
A) Battery-operated devices
B) Household mains
C) Transformers
D) Electric poles
Answer: Battery-operated devices
16. AC is used in
A) Household mains electricity
B) Flashlight
C) Battery-operated devices
D) None
Answer: Household mains electricity
17. Step-up transformer increases
A) Voltage
B) Current
C) Resistance
D) Power
Answer: Voltage
18. Step-down transformer decreases
A) Voltage
B) Current
C) Resistance
D) Power
Answer: Voltage
19. In domestic electric circuits, live wire is
A) Red or brown
B) Blue
C) Green
D) Yellow
Answer: Red or brown
20. Neutral wire in domestic circuit is
A) Blue or black
B) Red
C) Green
D) Yellow
Answer: Blue or black
21. Earth wire in domestic circuit is
A) Green or yellow-green
B) Red
C) Blue
D) Brown
Answer: Green or yellow-green
22. Earth wire provides
A) Safety by carrying current to ground in case of fault
B) Live voltage
C) Neutral flow
D) Resistance
Answer: Safety by carrying current to ground in case of fault
23. Fuse is connected in
A) Live wire in series
B) Neutral wire
C) Earth wire
D) Parallel
Answer: Live wire in series
24. Rating of domestic fuse is
A) 1–5 A or 5–15 A
B) 50 A
C) 100 A
D) None
Answer: 1–5 A or 5–15 A
25. Function of fuse is
A) Protect electrical appliances from excess current
B) Increase voltage
C) Decrease resistance
D) None
Answer: Protect electrical appliances from excess current
26. Electric current in series circuit is
A) Same in all parts of the circuit
B) Different in each part
C) Zero
D) Varies randomly
Answer: Same in all parts of the circuit
27. Electric current in parallel circuit is
A) Divided among branches
B) Same in all parts
C) Zero
D) Random
Answer: Divided among branches
Electricity – CBSE Class 10
28. Voltage across components in series
A) Divides among components
B) Same across each
C) Zero
D) None
Answer: Divides among components
29. Voltage across components in parallel
A) Same across each component
B) Divides among components
C) Zero
D) None
Answer: Same across each component
30. Domestic circuits are designed for
A) Safety and efficiency
B) Only current flow
C) Only voltage
D) None
Answer: Safety and efficiency
31. AC can be transmitted over long distance using
A) Transformers
B) Batteries
C) DC generators
D) Switches
Answer: Transformers
32. DC cannot be easily transmitted over long distances because
A) High power loss
B) Low voltage
C) High frequency
D) None
Answer: High power loss
33. Frequency of AC means
A) Number of cycles per second
B) Voltage per second
C) Resistance
D) Current
Answer: Number of cycles per second
34. 1 Hz frequency means
A) 1 cycle per second
B) 50 cycles per second
C) 100 cycles per second
D) 1 rotation
Answer: 1 cycle per second
35. Advantages of AC include
A) Easy voltage transformation, less transmission loss
B) Same as DC
C) Cannot be transmitted
D) None
Answer: Easy voltage transformation, less transmission loss
36. Main electric supply in homes is
A) AC
B) DC
C) Battery
D) None
Answer: AC
37. Electrical devices that operate on DC include
A) Flashlights, laptops
B) Refrigerator
C) Electric heater
D) Electric iron
Answer: Flashlights, laptops
38. Earth wire is connected to
A) Metal body of appliance
B) Live wire
C) Neutral wire
D) Fuse
Answer: Metal body of appliance
39. Short-circuit occurs when
A) Live and neutral come in direct contact
B) Fuse melts
C) Resistance increases
D) Voltage decreases
Answer: Live and neutral come in direct contact
Electricity – CBSE Class 10
40. Overload occurs when
A) More appliances are connected than rated current
B) Voltage decreases
C) Current stops
D) Fuse works normally
Answer: More appliances are connected than rated current
41. Safety measures in domestic circuits include
A) Fuse, Earth wire, Switches
B) Only switches
C) Only fuse
D) None
Answer: Fuse, Earth wire, Switches
42. Direction of AC reverses
A) Periodically
B) Never
C) Once only
D) Randomly
Answer: Periodically
43. In AC, current varies from
A) Zero to maximum and back
B) Constant
C) One direction only
D) None
Answer: Zero to maximum and back
44. Frequency of AC is measured in
A) Hertz (Hz)
B) Ampere
C) Volt
D) Ohm
Answer: Hertz (Hz)
45. Transformer works only with
A) AC
B) DC
C) Both
D) None
Answer: AC
46. Domestic electric circuits are generally
A) Parallel
B) Series
C) Open
D) Short
Answer: Parallel
47. Live wire in AC carries
A) Current at high potential
B) Neutral current
C) Ground current
D) Zero voltage
Answer: Current at high potential
48. Neutral wire carries
A) Current back to supply
B) High voltage
C) Fuse current
D) None
Answer: Current back to supply
49. Switch is connected in
A) Live wire
B) Neutral wire
C) Earth wire
D) Parallel
Answer: Live wire
50. AC is preferred over DC in power distribution because
A) Voltage can be stepped up or down using transformers
B) AC is safer
C) DC is cheaper
D) AC cannot be transmitted
Answer: Voltage can be stepped up or down using transformers
Also Read: Heredity and Evolution – CBSE Class 10