Heating Effect of Electric Current

Q. A resistance coil is made by combining two 2.5 ohm resistances in series. A 1.0 V steady voltage is applied across the two ends of the coil for 5 minutes. The heat generated is:

Q. Question 1
Illustarte the following effects of electric current:
(a) Heating effect
(b) Chemical effect
(c) Magnetic effect

Q. How do u calculate the total electrical energy?

Q.

If four resistances each of values 1 ohm are connected in series, resultant resistance will be in:

1. 1

2. 0

3. 4

4. 3

Q. You are given three bulbs $25W$, $40W$ and $60W$. Which of them has the lowest resistance?

1. $25$ watt bulb
2. $40$ watt bulb
3. Insufficient data
4. $60$ watt bulb

Q.

Write one expression for the electrical energy in terms of its potential difference, resistance and time.

Q. If the direct transmission method with a cable of resistance $0.4\Omega k{m}^{-1}$ is used, the power dissipation (in %) during transmission is

1. 50
2. 30
3. 20
4. 40

Q.

How does the heat produced in a wire or a conductor depend upon the resistance of the conductor?

Q.

How does the amount of heat produced in a resistor depend upon current?

Q. An electric heater of resistance $200\Omega$ . At what rate will heat be produced in it, when current of $2.5A$ flow through it.

Q. A fuse is rated $8$A. Can it be used with an electrical appliance rated $5$KW, $200$V? Give a reason.

Q. ntTwo electric bulbs rated 50 W and 100 V are glowing at full power, when used in parallel with a battery of emf 120 V and internal resistance 10 ohm.The maximum no. of bulbs that can be connected in the circuit when glowing at full powern nta)6n ntb)4n ntc)2n ntd)8n

Q. A $25$ watt, $220$ volt bulb and a $100$ watt , $220$ volt bulbs are connected in series across $440$ volt line

1. only $100$ watt bulbs will fuse
2. only $25$ watt bulbs will fuse
3. none of these bulbs will fuse
4. both bulbs will fuse

Q. If two wires $1mm$ and $2mm$ thick are made of same mass of copper connected in series and current is passed through them, then heat produced in the wires is in the ratio.

1. $2:1$
2. $4:1$
3. $16:1$
4. $8:1$

Q.

Choose the substance that is used to make the filament of an electric bulb?

1. Tungsten

2. Copper

3. Aluminium

4. Mercury

Q. An electric kettle of power 1 kw runs at 220 v potential. The current flowing
in the kettle is,
a) 4.55 amp
b) 45.5 amp
c) 455 amp
d) 0.455 amp

Q. A potential clifference of $220V$ is applied across a resistance of $440$$\Omega$ in an electrical appliance. Calculate the current drawn and the heat energy produced in $20seconds$.

1. $2400J$
2. $2300J$
3. $2500J$
4. $2200J$

Q. An electric bulb is rated 220V and 100W. When it is operated on 110V, the power consumed will be :

1. 100W
2. 75W
3. 50W
4. 25W

Q. Why electric current is scalar?

Q. Two resistor $R$ and $2R$ are connected in parallel in an electric circuit. The thermal energy developed in $R$ and $2R$ are in the ratio of

1. $1:4$
2. $4:1$
3. $1:2$
4. $2:1$

Q. Why electric flux =E. ds?Is there any Mathematical derivation for this to know why electric flux! =E. is?

Q.

Three lamps $100\mathrm{W},60\mathrm{W}$ and $40\mathrm{W}$ respectively are connected in parallel to a power supply of $220\mathrm{V}$. Calculate (a) total energy consumed (b) total resistance of arrangement (c) cost of keeping them lighted for 6 hours daily for 30 days, if cost of electricity per unit is ₹ 2.80.

Q. An electric motor driven pump fills an overhead tank placed at a height of 20 m from the ground-level sump at a rate of 20, 000 litre water per hour.The motor has an operating resistance of $22\Omega$ and is connected across a 220 V source.The efficiency of this motor is (Use$g=9.8m/s^2)$

1. $73.5\%$
2. $22.5\%$
3. $49.5\%$
4. $12.5\%$

Q. A lightbulb uses energy at a rate of $25.0Watts$.
If the current through the lightbulb is $2.00A$. What is the resistance of the bulb?

1. $6.25ohm$
2. $12.5ohm$
3. $0.0800ohm$
4. $100.0ohm$
5. $50.0ohm$

Q. Four bulbs having powers 25 W, 40 W, 60 W and 100 W are connected in series and this combination is connected across the mains. Find which bulb has highest potential difference and lowest potential difference ?

Q. Two identical heater wires are first connected in series and then in parallel with a source of electricity. The ratio of heat produced in the two cases ?

1. $2:1$
2. $1:2$
3. $4:1$
4. $1:4$

Q. A bulbs is connected to a battery of p.d. 4 V and internal resistance $2.5\Omega$. A stedy current of 0.5 A
(i) the total energy supplied by the battery in 10 minutes,
(ii) the resistance of the bulb, and
(iii) the energy displated in the bulb in 10 minutes

Q. When the current and voltage of an electric circuit is given. Then power can be calculated by:

1. multiplying the current by the difference between the voltage going into and going out of the device
2. multiplying the resistance by the resistance and the current
3. multiplying the voltage by the difference between the current going into and going out of the device
4. multiplying the current by the resistance
5. multiplying the current by the voltage

Q. Figure shows three resistor configurations $R1,R2$ and $R3$ connected to $3V$ battery. If the power dissipated by the configuration $R1,R2$ and $R3$ is $P1,P2$ and $P3$, respectively, then

1. $P1>P2>P3$
2. $P1>P3>P2$
3. $P2>P1>P3$
4. $P3>P2>P1$

Q. In the circuit shown, the heat produced in 5$\Omega$ resistor is 10 calorie/sec. The heat produced/sec in 4$\Omega$ resistor will be :

1. 1 cal
2. 2 cal
3. 3 cal
4. 4 cal