PHYSICS | MOST PREDICTED QUESTIONS

CHAPTER 1

Effects of Electric Current

1 / 177

If a 60W light bulb operates on a 120V supply, what is the current through the bulb?

2 / 177

An LED bulb with a power rating of 8W is used for 10 hours. If the cost of electricity is ₹0.12 per kWh, what is the cost of operating the bulb for 10 hours?

3 / 177

What is the current through a 20-ohm resistor connected to a 10V power supply?

4 / 177

How does an induction cooktop heat food?

5 / 177

A circuit contains a 24V battery and three resistors (4 ohms, 6 ohms, and 12 ohms) connected in series. What is the total resistance and current in the circuit?

6 / 177

A circuit consists of a 9V battery and a series combination of a 3-ohm and a 6-ohm resistor. What is the total current in the circuit?

7 / 177

Why are resistors important in electronic devices?

8 / 177

A circuit consists of a 9V battery and two resistors (3 ohms and 6 ohms) in parallel. What is the total resistance and current in the circuit?

9 / 177

What is the primary component of an LED bulb?

10 / 177

Why are LED bulbs more energy-efficient than incandescent bulbs?

11 / 177

An LED bulb operates at 9V and draws 0.5A of current. What is the power consumption of the bulb?

12 / 177

How does an electric motor convert electrical energy into mechanical energy?

13 / 177

If a 100W light bulb operates on a 230V supply, what is the resistance of the bulb?

14 / 177

A 240V electric kettle has a resistance of 30 ohms. What is the power consumption of the kettle?

15 / 177

How does a digital thermometer measure temperature?

16 / 177

If a 9V battery is connected to two resistors (12 ohms and 18 ohms) in parallel, what is the total current supplied by the battery?

17 / 177

What is the equivalent resistance of a 20-ohm and a 30-ohm resistor connected in parallel?

18 / 177

If an LED bulb with a power rating of 9W is used for 5 hours daily, what is the total energy consumption in a month (30 days)?

19 / 177

How do LED bulbs support the use of renewable energy sources?

20 / 177

If a 60W light bulb operates on a 120V supply, what is the resistance of the bulb?

21 / 177

If a 50W appliance operates for 4 hours, how much energy is consumed?

22 / 177

How do smart LED bulbs enhance home automation?

23 / 177

A circuit consists of a 24V battery and three resistors (4 ohms, 6 ohms, and 12 ohms) in parallel. What is the total current supplied by the battery?

24 / 177

How does an incandescent lamp work?

25 / 177

How do LED bulbs enhance the aesthetics of home decor?

26 / 177

What is the power consumption of a 120V, 60W appliance if it is used for 5 hours?

27 / 177

What is the color code for a 220-ohm resistor with a tolerance of 5%?

28 / 177

A 120V electric heater has a resistance of 30 ohms. What is the power consumed by the heater?

29 / 177

How does an electric heater work using the principle of Joule’s Law?

30 / 177

What is the total resistance of four 8-ohm resistors connected in series?

31 / 177

How do LED bulbs improve energy efficiency in commercial buildings?

32 / 177

A circuit has a total resistance of 15 ohms and a current of 4A. What is the total voltage?

33 / 177

What is the purpose of a circuit breaker?

34 / 177

Why are LED bulbs preferred for use in flashlights?

35 / 177

If a 12V battery supplies 2A to a resistor, what is the power dissipated by the resistor?

36 / 177

What is the advantage of using a parallel circuit for household wiring?

37 / 177

What is a resistor?

38 / 177

What is the power dissipated by a 10-ohm resistor with 2A of current flowing through it?

39 / 177

How much power is dissipated by a 10-ohm resistor with a current of 2A flowing through it?

40 / 177

If a 60W appliance operates on a 120V supply, what is the resistance of the appliance?

41 / 177

What is the primary purpose of a capacitor in an electronic circuit?

42 / 177

What is the voltage across a 15-ohm resistor if 3A of current flows through it?

43 / 177

A 12V battery is connected to a series combination of a 3-ohm and a 9-ohm resistor. What is the voltage drop across the 9-ohm resistor?

44 / 177

If a 24V battery is connected to a series combination of a 6-ohm and a 12-ohm resistor, what is the power dissipated by the 6-ohm resistor?

45 / 177

What causes short circuiting in an electrical circuit?

46 / 177

What advantage do LED bulbs have in refrigerated display cases in supermarkets?

47 / 177

Why are LED bulbs ideal for task lighting?

48 / 177

What does Joule’s Law state?

49 / 177

How are resistors connected in a series circuit?

50 / 177

What is the total resistance of three 10-ohm resistors connected in series?

51 / 177

Why are electric toothbrushes more effective at cleaning teeth than manual toothbrushes?

52 / 177

How does a microwave oven use the effects of electric current to cook food?

53 / 177

Why are LED bulbs more suitable for outdoor lighting compared to incandescent bulbs?

54 / 177

A 10W LED bulb has a lifespan of 25,000 hours. How much total energy will it consume over its lifetime?

55 / 177

If an LED bulb emits 800 lumens and operates at 8W, what is its luminous efficacy?

56 / 177

What is the main difference between resistors in series and parallel connections?

57 / 177

How are resistors connected in a parallel circuit?

58 / 177

What is the total resistance if a 12-ohm resistor and a 4-ohm resistor are connected in parallel?

59 / 177

A 9V battery is connected to a parallel combination of two resistors (9 ohms and 18 ohms). What is the total current supplied by the battery?

60 / 177

How do arc lamps produce light?

61 / 177

How does an electric water heater maintain a constant water temperature?

62 / 177

What happens to the current in a parallel circuit if one resistor is removed?

63 / 177

If a 12V battery is connected to a parallel combination of three 36-ohm resistors, what is the total current supplied by the battery?

64 / 177

A 100-ohm resistor is connected in parallel with a 200-ohm resistor. What is the equivalent resistance?

65 / 177

How does an incandescent lamp produce light?

66 / 177

What is voltage?

67 / 177

A circuit consists of a 12V battery and three resistors (2 ohms, 3 ohms, and 5 ohms) in series. What is the total resistance and current in the circuit?

68 / 177

How does an electric blanket use the heating effect of electric current?

69 / 177

What is the primary reason LED bulbs have a longer lifespan than incandescent bulbs?

70 / 177

Why are LED bulbs preferred for use in grow lights for plants?

71 / 177

What is the primary benefit of using LED bulbs in automotive lighting?

72 / 177

How do LED bulbs enhance the safety of holiday lighting displays?

73 / 177

What is the gauge of a wire?

74 / 177

What determines the brightness of an LED?

75 / 177

If a 5-ohm resistor and a 10-ohm resistor are connected in series to a 15V battery, what is the current through the circuit?

76 / 177

How do electric cars help reduce urban air pollution?

77 / 177

What is the color code for a 1k-ohm resistor with a tolerance of 5%?

78 / 177

What is the function of a fuse in an electric circuit?

79 / 177

A 240V electric kettle has a power rating of 2.4kW. What is the resistance of the kettle?

80 / 177

What is the primary application of a Zener diode?

81 / 177

What is the lighting effect of electric current?

82 / 177

What is amperage?

83 / 177

How does a thermistor function in a circuit?

84 / 177

What happens to the total power in a circuit if more resistors are added in series?

85 / 177

Why are LED bulbs preferred over incandescent bulbs for home lighting?

86 / 177

What is the heating effect of electric current?

87 / 177

How does a diode function in an electric circuit?

88 / 177

Why do electric ovens use heating elements at both the top and bottom?

89 / 177

How does the color temperature of an LED bulb affect its use in different settings?

90 / 177

A 12V battery is connected to three resistors (3 ohms, 6 ohms, and 12 ohms) in parallel. What is the total current supplied by the battery?

91 / 177

What is electric power measured in?

92 / 177

How much energy is consumed by a 100W appliance operating for 3 hours?

93 / 177

How does a dimmer switch control the brightness of a light bulb?

94 / 177

Why are electric fans more efficient than air conditioners for cooling?

95 / 177

How does a smart thermostat improve energy efficiency in a home?

96 / 177

What is the benefit of using LED bulbs in outdoor lighting?

97 / 177

If an LED bulb has an efficiency of 85% and consumes 15W of electrical power, what is the actual light output in watts?

98 / 177

Who is James Prescott Joule?

99 / 177

A 100W light bulb operates on a 120V supply. What is the current through the bulb?

100 / 177

Why are LED streetlights preferred by many municipalities?

101 / 177

How long can a 9V battery with a capacity of 500mAh power a 45mA LED?

102 / 177

An LED bulb is rated at 7W and produces 560 lumens. What is its luminous efficacy?

103 / 177

If a 100-ohm resistor is connected to a 50V power supply, what is the power dissipated by the resistor?

104 / 177

A circuit consists of a 24V battery and a series combination of a 4-ohm and a 2-ohm resistor. What is the current in the circuit?

105 / 177

How does an electric fuse protect household appliances?

106 / 177

Why are electric lawn mowers considered more environmentally friendly than gas-powered ones?

107 / 177

A 240V electric heater has a resistance of 48 ohms. What is the current flowing through the heater?

108 / 177

What is the voltage drop across a 6-ohm resistor with 2A of current flowing through it?

109 / 177

A 150W appliance operates on a 220V supply. What is the current flowing through the appliance?

110 / 177

A 100-ohm resistor is connected to a 50V power supply. What is the current flowing through the resistor?

111 / 177

How does a refrigerator use the effects of electric current to keep food cold?

112 / 177

What is the function of a light-emitting diode (LED) in electronic displays?

113 / 177

If a 40W light bulb is connected to a 220V supply, what is the current flowing through the bulb?

114 / 177

A 24V power supply is connected to a series combination of two resistors (8 ohms and 16 ohms). What is the voltage drop across the 16-ohm resistor?

115 / 177

How does a dimmer switch control the brightness of a light bulb?

116 / 177

A 100W appliance operates on a 240V supply. What is the resistance of the appliance?

117 / 177

What is the practical use of a capacitor in everyday electronic devices?

118 / 177

How do electric irons utilize the heating effect of electric current?

119 / 177

If a 240V appliance draws 5A of current, what is its power consumption?

120 / 177

Why are electric showers equipped with a temperature control system?

121 / 177

A 12V battery is connected to a series combination of a 6-ohm and a 3-ohm resistor. What is the power dissipated by the 6-ohm resistor?

122 / 177

A 5-ohm resistor and a 20-ohm resistor are connected in parallel. What is their equivalent resistance?

123 / 177

How much current flows through a 60W light bulb connected to a 120V supply?

124 / 177

Why do electric cars use regenerative braking?

125 / 177

What is the equivalent resistance of four 16-ohm resistors connected in parallel?

126 / 177

How is electric power defined?

127 / 177

What is the function of a rheostat?

128 / 177

What is the equivalent resistance of a 10-ohm and a 30-ohm resistor connected in parallel?

129 / 177

How do thermistors help in modern home appliances?

130 / 177

A 24V battery is connected to a series combination of two resistors (4 ohms and 8 ohms). What is the power dissipated by the 8-ohm resistor?

131 / 177

A circuit contains a 12V battery and two resistors (6 ohms and 3 ohms) connected in series. What is the voltage drop across the 6-ohm resistor?

132 / 177

Why are series circuits used in certain applications?

133 / 177

Why are compact fluorescent lamps (CFLs) considered more efficient than incandescent bulbs?

134 / 177

A 150W appliance operates on a 220V supply. What is the resistance of the appliance?

135 / 177

A 24-ohm resistor and a 6-ohm resistor are connected in series to a 12V battery. What is the voltage drop across the 24-ohm resistor?

136 / 177

What is the voltage across a 5-ohm resistor if 4A of current flows through it?

137 / 177

What is the main advantage of LED bulbs over incandescent lamps?

138 / 177

What is the power dissipated by a 5-ohm resistor with 4A of current flowing through it?

139 / 177

If a 240V appliance draws 3A of current, what is its power consumption?

140 / 177

What is the role of nichrome in heating devices?

141 / 177

In a parallel circuit with three resistors, what happens if one resistor is removed?

142 / 177

How do LED bulbs improve the functionality of smart home systems?

143 / 177

What is the application of the heating effect of electric current in electronic devices?

144 / 177

What is the total resistance of five 10-ohm resistors connected in parallel?

145 / 177

What is a short circuit?

146 / 177

How do LED bulbs contribute to reducing greenhouse gas emissions?

147 / 177

How does a surge protector safeguard electronic devices?

148 / 177

What is the role of circuit breakers in residential electrical systems?

149 / 177

What is the total resistance of three 15-ohm resistors connected in parallel?

150 / 177

What is the power output of a circuit with a voltage of 24V and a current of 3A?

151 / 177

What is the voltage drop across a 5-ohm resistor with 3A of current flowing through it?

152 / 177

Why do modern homes use circuit breakers instead of fuses?

153 / 177

How do LED bulbs contribute to reducing light pollution?

154 / 177

How does an electric kettle quickly heat water?

155 / 177

If a 120V circuit has a total resistance of 30 ohms, what is the current flowing through the circuit?

156 / 177

A 12V battery is connected to a series combination of a 3-ohm, 6-ohm, and 9-ohm resistor. What is the voltage drop across the 6-ohm resistor?

157 / 177

Why are LEDs more energy-efficient than incandescent bulbs?

158 / 177

A 240V heater has a resistance of 60 ohms. What is the power consumed by the heater?

159 / 177

A 12V battery is connected to a series combination of three resistors (2 ohms, 4 ohms, and 6 ohms). What is the voltage drop across the 4-ohm resistor?

160 / 177

If two resistors (4 ohms and 12 ohms) are connected in parallel, what is their equivalent resistance?

161 / 177

If a 60W appliance operates for 5 hours, how much energy is consumed?

162 / 177

What is the construction of an LED bulb?

163 / 177

If an LED bulb has a luminous efficacy of 100 lumens per watt and a power consumption of 10W, what is its total luminous output?

164 / 177

Why are LED bulbs considered more environmentally friendly than traditional bulbs?

165 / 177

Why do electric heaters have a thermostat?

166 / 177

If a heater has a resistance of 25 ohms and operates on a 200V supply, what is the power consumed by the heater?

167 / 177

A 24V battery is connected to a parallel combination of three resistors (8 ohms, 12 ohms, and 24 ohms). What is the total current supplied by the battery?

168 / 177

Why are photovoltaic cells used in solar panels?

169 / 177

What is the color code for a 4700-ohm resistor with a tolerance of 10%?

170 / 177

A 9V battery is connected to a parallel combination of two 18-ohm resistors. What is the total current supplied by the battery?

171 / 177

How does a hair dryer convert electrical energy into heat?

172 / 177

What is the total resistance of three 10-ohm resistors connected in parallel?

173 / 177

What is the function of a resistor in a circuit?

174 / 177

What is the total resistance of two 16-ohm resistors connected in parallel?