Q. At some location on earth the horizontal component of earth's magnetic field is $18 \times 10^{-6}$ T. At this location, magnetic neeedle of length 0.12 m and pole strength 1.8 Am is suspended from its mid-point using a thread, it makes $45^{\circ}$ angle with horizontal in equilibrium. To keep this needle horizontal, the vertical force that should be applied at one of its ends is :

JEE Main JEE Main 2019

$3.6 \times 10^{-5} \; N$

$6.5 \times 10^{-5} \; N$

$1.3 \times 10^{-5} \; N$

$1.8 \times 10^{-5} \; N$

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Questions from JEE Main 2019

1. A rod of mass 'M' and length '2L' is suspended at its middle by a wire. It exhibits torsional oscillations; If two masses each of 'm' are attached at distance 'L/2' from its centre on both sides, it reduces the oscillation frequency by 20%. The value of ratio m/M is close to :

2. A 15 g mass of nitrogen gas is enclosed in a vessel at a temperature $27^{\circ}C$. Amount of heat transferred to the gas, so that rms velocity of molecules is doubled, is about :
[Take R = 8.3 J/ K mole]

3. A particle is executing simple harmonic motion (SHM) of amplitude A, along the x-axis, about x = 0. When its potential Energy (PE) equals kinetic energy (KE), the position of the particle will be :

4. A musician using an open flute of length 50 cm produces second harmonic sound waves. A person runs towards the musician from another end of a hall at a speed of 10 km/h. If the wave speed is 330 m/s, the frequency heard by the running person shall be close to :

5. In a communication system operating at wavelength 800 nm, only one percent of source frequency is available as signal bandwidth. The number of channels accomodated for transmitting TV signals of band width 6 MHz are (Take velocity of light $c = 3 \times 10^8 m/s,h = 6.6 \times 10^{-34} J-s)$

6. Two point charges $q_1( \sqrt{10} \mu C)$ and $q^2(-25 \; \mu C)$ are placed on the x-axis at x = l m and x = 4 m respectively. The electric field (in V/m) at a point y = 3 m on y-axis is, $\left[\text{take} \frac{1}{4\pi\varepsilon_{0}} = 9\times10^{9} Nm^{2} C^{-2}\right] $

7. A parallel plate capacitor with square plates is filled with four dielectrics of dielectric constants $K_1, K_2, K_3, K_4$ arranged as shown in the figure.
The effective dielectric constant K will be :

8. A rod of length 50cm is pivoted at one end. It is raised such that if makes an angle of 30° from the horizontal as shown and released from rest. Its angular speed when it passes through the horizontal (in rad $s^{-1}$) will be $(g = 10ms^{-2})$

9. One of the two identical conducting wires of length L is bent in the form of a circular loop and the other one into a circular coil of N identical turns. If the same current is passed in both, the ratio of the magnetic field at the central of the loop $(B_L)$ to that at the centre of the coil $(B_C)$ , i.e., $R \frac{B_L}{B_C}$ will be

10. The energy required to take a satellite to a height 'h' above Earth surface (radius of Earth = $6.4 \times 10^3 \; km) $ is $E_1$ and kinetic energy required for the satellite to be in a circular orbit at this height is $E_2$. The value of h for which $E_1 $ and $E_2$ are equal, is:

Physics Most Viewed Questions

1. An AC ammeter is used to measure current in a circuit. When a given direct current passes through the circuit, the AC ammeter reads 3 A. When another alternating current passes through the circuit, the AC ammeter reads 4 A. Then the reading of this ammeter, if DC and AC flow through the circuit simultaneously, is

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2. Assertion : Perspiration from human body helps in cooling the body
Reason : A thin layer of water on the skin enhances its emissivity.

AIIMS 2006 Thermal Properties Of Matter

3. The speed of sound through oxygen at T K is v m$s^{-1}$. As the temperature becomes 2T and oxygen gas dissociates into atomic oxygen, the speed of sound

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4. If voltage across a bulb rated 220 volt-100 watt drops by $2.5\%$ of its rated value, the percentage of the rated value by which the power would decrease is

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5. If the dimensions of a physical quantity are given by $\ce{M^aL^bT^c}$, then the physical quantity will be

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6. There are 26 tuning forks arranged in the decreasing order of their frequencies. Each tuning fork gives 3 beats with the next. The first one is octave of the last. What is the frequency of 18th tuning fork?

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7. The electric resistance of a certain wire of iron is $R$. If its length and radius are both doubled, then

JIPMER 2015 Current Electricity

8. A quarter horse power motor runs at a speed of 600 rpm. Assuming 40% efficiency, the work done by the motor in one rotation will be

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9. A cannon of mass I 000 kg, located at the base of an inclined plane fires a shelI of mass 100 kg in a horizontal direction with a velocity 180 $kmh^{-1}$. The angle of inclination of the inclined plane with the horizontal is 45$^{\circ}$. The coefficient of friction between the cannon and the inclined plane is 0.5. The height, in metre, to which the cannon ascends the inclined plane as a result of the recoiI is (g = 10 $ms^{-1})$

EAMCET 2004 Laws Of Motion

10. Two charges $ q_1 $ and $q_2$ are placed 30 cm apart, as shown in the figure. A third charge $q_3$ is moved along the arc of a circle of radius 40cm from C to D. The change in the potential energy of the system is $ \frac{q_3}{ 4 \pi \varepsilon_0}$ k. where k is

AIPMT 2005 Electrostatic Potential And Capacitance

$3.6 \times 10^{-5} \; N$

$6.5 \times 10^{-5} \; N$

$1.3 \times 10^{-5} \; N$

$1.8 \times 10^{-5} \; N$

$\mu B\sin45^{\circ}=F \frac{\ell}{2} \sin45^{\circ} $
$ F =2\mu B$

Questions from JEE Main 2019

1. A rod of mass 'M' and length '2L' is suspended at its middle by a wire. It exhibits torsional oscillations; If two masses each of 'm' are attached at distance 'L/2' from its centre on both sides, it reduces the oscillation frequency by 20%. The value of ratio m/M is close to :

2. A 15 g mass of nitrogen gas is enclosed in a vessel at a temperature $27^{\circ}C$. Amount of heat transferred to the gas, so that rms velocity of molecules is doubled, is about :
[Take R = 8.3 J/ K mole]

3. A particle is executing simple harmonic motion (SHM) of amplitude A, along the x-axis, about x = 0. When its potential Energy (PE) equals kinetic energy (KE), the position of the particle will be :

4. A musician using an open flute of length 50 cm produces second harmonic sound waves. A person runs towards the musician from another end of a hall at a speed of 10 km/h. If the wave speed is 330 m/s, the frequency heard by the running person shall be close to :

5. In a communication system operating at wavelength 800 nm, only one percent of source frequency is available as signal bandwidth. The number of channels accomodated for transmitting TV signals of band width 6 MHz are (Take velocity of light $c = 3 \times 10^8 m/s,h = 6.6 \times 10^{-34} J-s)$

6. Two point charges $q_1( \sqrt{10} \mu C)$ and $q^2(-25 \; \mu C)$ are placed on the x-axis at x = l m and x = 4 m respectively. The electric field (in V/m) at a point y = 3 m on y-axis is, $\left[\text{take} \frac{1}{4\pi\varepsilon_{0}} = 9\times10^{9} Nm^{2} C^{-2}\right] $

7. A parallel plate capacitor with square plates is filled with four dielectrics of dielectric constants $K_1, K_2, K_3, K_4$ arranged as shown in the figure.
The effective dielectric constant K will be :

8. A rod of length 50cm is pivoted at one end. It is raised such that if makes an angle of 30° from the horizontal as shown and released from rest. Its angular speed when it passes through the horizontal (in rad $s^{-1}$) will be $(g = 10ms^{-2})$

10. The energy required to take a satellite to a height 'h' above Earth surface (radius of Earth = $6.4 \times 10^3 \; km) $ is $E_1$ and kinetic energy required for the satellite to be in a circular orbit at this height is $E_2$. The value of h for which $E_1 $ and $E_2$ are equal, is:

Physics Most Viewed Questions

2. Assertion : Perspiration from human body helps in cooling the body
Reason : A thin layer of water on the skin enhances its emissivity.

3. The speed of sound through oxygen at T K is v m$s^{-1}$. As the temperature becomes 2T and oxygen gas dissociates into atomic oxygen, the speed of sound

4. If voltage across a bulb rated 220 volt-100 watt drops by $2.5\%$ of its rated value, the percentage of the rated value by which the power would decrease is

5. If the dimensions of a physical quantity are given by $\ce{M^aL^bT^c}$, then the physical quantity will be

6. There are 26 tuning forks arranged in the decreasing order of their frequencies. Each tuning fork gives 3 beats with the next. The first one is octave of the last. What is the frequency of 18th tuning fork?

7. The electric resistance of a certain wire of iron is $R$. If its length and radius are both doubled, then

8. A quarter horse power motor runs at a speed of 600 rpm. Assuming 40% efficiency, the work done by the motor in one rotation will be

10. Two charges $ q_1 $ and $q_2$ are placed 30 cm apart, as shown in the figure. A third charge $q_3$ is moved along the arc of a circle of radius 40cm from C to D. The change in the potential energy of the system is $ \frac{q_3}{ 4 \pi \varepsilon_0}$ k. where k is

Latest Updates

$3.6 \times 10^{-5} \; N$

$6.5 \times 10^{-5} \; N$

$1.3 \times 10^{-5} \; N$

$1.8 \times 10^{-5} \; N$

$\mu B\sin45^{\circ}=F \frac{\ell}{2} \sin45^{\circ} $ $ F =2\mu B$

Questions from JEE Main 2019

1. A rod of mass 'M' and length '2L' is suspended at its middle by a wire. It exhibits torsional oscillations; If two masses each of 'm' are attached at distance 'L/2' from its centre on both sides, it reduces the oscillation frequency by 20%. The value of ratio m/M is close to :

2. A 15 g mass of nitrogen gas is enclosed in a vessel at a temperature $27^{\circ}C$. Amount of heat transferred to the gas, so that rms velocity of molecules is doubled, is about : [Take R = 8.3 J/ K mole]

3. A particle is executing simple harmonic motion (SHM) of amplitude A, along the x-axis, about x = 0. When its potential Energy (PE) equals kinetic energy (KE), the position of the particle will be :

4. A musician using an open flute of length 50 cm produces second harmonic sound waves. A person runs towards the musician from another end of a hall at a speed of 10 km/h. If the wave speed is 330 m/s, the frequency heard by the running person shall be close to :

5. In a communication system operating at wavelength 800 nm, only one percent of source frequency is available as signal bandwidth. The number of channels accomodated for transmitting TV signals of band width 6 MHz are (Take velocity of light $c = 3 \times 10^8 m/s,h = 6.6 \times 10^{-34} J-s)$

6. Two point charges $q_1( \sqrt{10} \mu C)$ and $q^2(-25 \; \mu C)$ are placed on the x-axis at x = l m and x = 4 m respectively. The electric field (in V/m) at a point y = 3 m on y-axis is, $\left[\text{take} \frac{1}{4\pi\varepsilon_{0}} = 9\times10^{9} Nm^{2} C^{-2}\right] $

7. A parallel plate capacitor with square plates is filled with four dielectrics of dielectric constants $K_1, K_2, K_3, K_4$ arranged as shown in the figure. The effective dielectric constant K will be :

8. A rod of length 50cm is pivoted at one end. It is raised such that if makes an angle of 30° from the horizontal as shown and released from rest. Its angular speed when it passes through the horizontal (in rad $s^{-1}$) will be $(g = 10ms^{-2})$

10. The energy required to take a satellite to a height 'h' above Earth surface (radius of Earth = $6.4 \times 10^3 \; km) $ is $E_1$ and kinetic energy required for the satellite to be in a circular orbit at this height is $E_2$. The value of h for which $E_1 $ and $E_2$ are equal, is:

Physics Most Viewed Questions

2. Assertion : Perspiration from human body helps in cooling the body Reason : A thin layer of water on the skin enhances its emissivity.

3. The speed of sound through oxygen at T K is v m$s^{-1}$. As the temperature becomes 2T and oxygen gas dissociates into atomic oxygen, the speed of sound

4. If voltage across a bulb rated 220 volt-100 watt drops by $2.5\%$ of its rated value, the percentage of the rated value by which the power would decrease is

5. If the dimensions of a physical quantity are given by $\ce{M^aL^bT^c}$, then the physical quantity will be

6. There are 26 tuning forks arranged in the decreasing order of their frequencies. Each tuning fork gives 3 beats with the next. The first one is octave of the last. What is the frequency of 18th tuning fork?

7. The electric resistance of a certain wire of iron is $R$. If its length and radius are both doubled, then

8. A quarter horse power motor runs at a speed of 600 rpm. Assuming 40% efficiency, the work done by the motor in one rotation will be

10. Two charges $ q_1 $ and $q_2$ are placed 30 cm apart, as shown in the figure. A third charge $q_3$ is moved along the arc of a circle of radius 40cm from C to D. The change in the potential energy of the system is $ \frac{q_3}{ 4 \pi \varepsilon_0}$ k. where k is

Latest Updates

$\mu B\sin45^{\circ}=F \frac{\ell}{2} \sin45^{\circ} $
$ F =2\mu B$

2. A 15 g mass of nitrogen gas is enclosed in a vessel at a temperature $27^{\circ}C$. Amount of heat transferred to the gas, so that rms velocity of molecules is doubled, is about :
[Take R = 8.3 J/ K mole]

7. A parallel plate capacitor with square plates is filled with four dielectrics of dielectric constants $K_1, K_2, K_3, K_4$ arranged as shown in the figure.
The effective dielectric constant K will be :

2. Assertion : Perspiration from human body helps in cooling the body
Reason : A thin layer of water on the skin enhances its emissivity.