Question 1
Question: What is the SI unit of charge
Answer: The SI unit of charge is coulomb.
Question 2
Question: How many electrons constitute a charge equal to 1 C
Answer: 1 Coulomb of charge has 6.25 x 10^18 electrons.
Question 3
Question: State ohm's law.
Answer: When temperature and other physical parameters remain constant, the current flowing through a conductor is directly proportional to the potential difference across its ends.
Question 4
Question: Which effect of current is used in the following appliance? a) electric bulb b) immersion rod c) electric iron d) galvanometer
Answer: For electric bulb, immersion rod and electric iron, heating effect of current is used. For galvanometer magnetic effect of current is used.
Question 5
Question: Define watt and watt hour.
Answer: Watt is the unit of power. If 1 joule of energy is consumed in 1 second, we say the power of the device is 1 watt. Watt hour is the unit of energy. If a device with a power 1 watt works for 1 hour 1 watt hour amount of energy is consumed.
Question 6
Question: Which of the following graphs depict ohm's law.
Answer:
Graph (a) represents ohm's law since a straight line which shows that 'I' is directly proportional to 'V' (i.e., ohm's law).
Question 7
Question: On what factor's does the heating effect of current depend on.
Answer: The heating effect of current depends on
The square of the amount of current flowing
The resistance of the wire and
The time of flow of current
Question 8
Question: Name the instrument that measures the potential difference across the ends of a current carrying conductor. How is the instrument connected to the circuit?
Answer: Voltmeter measures the potential difference across the ends of a conductor. It is connected in parallel across the element through which current flows due to a certain potential difference.
Question 9
Question: When are several resistors in a circuit said to be connected in parallel?
Answer: Several resistors are said to be connected in parallel when the potential difference across the resistors remain the same.