Advertisements
Advertisements
Question
The diagram above shows a circuit with the key k open. Calculate :
(i) the resistance of the circuit when the key k is open.
(ii) the current drawn from the cell when the key k is open.
(iii) the resistance of the circuit when the key k is closed.
(iv) the current drawn from the cell when the key k is closed.
Advertisements
Solution
(i) when k is open
Req = 5Ω + 0.5 Ω = 5.5Ω
(ii) `i = v/(R_(eq))|_("case k open")`
`=(3.3v)/(5.5 Ω ) = 3/5 =0.6 A`
(iii) when k is closed,
`R_(eq) =(R_1R_2)/(R_1 + R_2) = (5xx5)/(5+5) = 2.5 Ω`
`R_(Total) = 2.5 Ω + 0.5 Ω = 3.0 Ω`
(iv) `i =v/(R_T) = 3.3/3.0 = 1.1A`
APPEARS IN
RELATED QUESTIONS
1 calorie = _________ joule.
Name the S.I unit of electrical energy. How is it related to Wh?
A simple electric circuit has 24 V battery and a resistor of 60 Ω. What will be the current in the circuit? The resistance of the connecting wires is negligible.
A simple electric circuit has a 30 V battery and a resistor ot 60 o. What will be the current in the circuit? The resistance of the oonnecting wires is negligible.
An electric current is passed through a metallic wire. The wire gets heated up. Give the reason. Is it possible to melt the wire by passing a heavy current?
Why is heating coil wound in the form of a helix in electric stove?
An electric kettle is rated 3kW, 250V. What should be the current capacity of the fuse with it?
Find the cost of operating an electric toaster for two hours if it draws 8 A current on a 110 volt circuit. The cost of electrical energy is Rs. 2.50 per kWh.
A consumer uses 4 lamps of 60 watt, 2 lamps of 40 watt, and 2 lamps of 100 watt. All these are used for 6 hour daily. Find the total bill for 30 days when the rate of energy is 75 paise per unit and the meter rent is Rs. 1.
A family uses 8 kW of power. Direct solar energy is incident on the horizontal surface at an average rate of 200 W per square meter. If 20% of this energy can be converted to useful electrical energy, how large an area is needed to supply 8 kW?
