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The energy equivalent of 0.5 g of a substance is :
An electron enters an electric field with its velocity in the direction of the electric lines of force. Then:
Which of the following is a natural polymer?
In a potentiometer arrangement, a cell of emf 1.25 V gives a balance point at 35.0 cm length of the wire. If the cell is replaced by another cell and the balance point shifts to 63.0 cm, then the emf of the second cell is:
A certain metallic surface is illuminated with monochromatic light of wavelength $\lambda$. The stopping potential for photoelectric current for this light is $3V_0$. If the same surface is illuminated with light of wavelength $2\lambda$, the stopping potential is $V_0$. The photoelectric effect's threshold wavelength for this surface is?
A capacitor of $2 \mu\text{F}$ is charged as shown in the figure. When the switch S is turned to position 2, the percentage of its stored energy dissipated is:
A football player is moving southward and suddenly turns eastward with the same speed to avoid an opponent. The force that acts on the player while turning is:
The number density of free electrons in a copper conductor is $8.5 \times 10^{28} \text{ m}^{-3}$. How long does an electron take to drift from one end of a wire $3.0 \text{ m}$ long to its other end? (The area of cross-section of the wire is $2.0 \times 10^{-6} \text{ m}^2$ and it is carrying a current of $3.0 \text{ A}$).
In the Wheatstone's bridge shown, P = 2 Ω, Q = 3 Ω, R = 6 Ω and S = 8 Ω. In order to obtain balance, shunt resistance across 'S' must be [SCRA 1998]
A cycle wheel of radius $0.5 \text{ m}$ is rotated with a constant angular velocity of $10 \text{ rad/s}$ in a region of a magnetic field of $0.1 \text{ T}$ which is perpendicular to the plane of the wheel. The EMF generated between its centre and the rim is:
A horizontal force $10 \text{ N}$ is applied to a block A as shown in figure. The mass of blocks A and B are $2 \text{ kg}$ and $3 \text{ kg}$, respectively. The blocks slide over a frictionless surface. The force exerted by block A on block B is:
A solid metallic sphere has a charge +3Q. Concentric with this sphere is a conducting spherical shell having charge –Q. The radius of the sphere is a and that of the spherical shell is b (b > a). What is the electric field at a distance R (a < R < b) from the centre?
The angular speed of a fly wheel moving with uniform angular acceleration changes from 1200 rpm to 3120 rpm in 16 seconds. The angular acceleration in $\text{rad/s}^2$ is
Figure shows a potentiometer with a cell of 2.0 V and internal resistance 0.40 Ω maintaining a potential drop across the resistor wire AB. A standard cell which maintains a constant emf of 1.02 V (for very moderate currents up to a few mA) gives a balance point at 67.3 cm length of the wire. To ensure very low currents drawn from the standard cell, a very high resistance of 600 kΩ is put in series with it, which is shorted close to the balance point. The standard cell is then replaced by a cell of unknown emf ε and the balance point found similarly, turns out to be at 82.3 cm length of the wire. The value of ε is:
A polythene piece rubbed with wool is found to have a negative charge of $3 \times 10^{-7}$ C. The transfer of mass from wool to polythene is:
The figure shows a 2.0 V potentiometer used for the determination of the internal resistance of a 1.5 V cell. The balance point of the cell in the open circuit is 76.3 cm. When a resistor of 9.5 Ω is used in the external circuit of the cell, the balance point shifts to 64.8 cm length of the potentiometer wire. The internal resistance of the cell is:
A force $F = 20 + 10y$ acts on a particle in y-direction where F is in newton and y in meter. Work done by this force to move the particle from $y = 0$ to $y = 1 \text{ m}$ is
A positively charged ball hangs from a silk thread. We put a positive test charge q₀ at a point and measure F/q₀, then it can be predicted that the electric field strength E
A rectangular, a square, a circular and an elliptical loop, all in the $(x-y)$ plane, are moving out of a uniform magnetic field with a constant velocity, $\vec{v} = v\hat{i}$. The magnetic field is directed along the negative $z$-axis direction. The induced emf, during the passage of these loops, out of the field region, will not remain constant for:
Limiting molar conductivities, for the given solutions, are: $\lambda^0_m(\text{H}_2\text{SO}_4) = x \text{ S cm}^2 \text{ mol}^{-1}$ $\lambda^0_m(\text{K}_2\text{SO}_4) = y \text{ S cm}^2 \text{ mol}^{-1}$ $\lambda^0_m(\text{CH}_3\text{COOK}) = z \text{ S cm}^2 \text{ mol}^{-1}$ From the data given above, it can be concluded that $\lambda^0_m$ in $(\text{S cm}^2 \text{ mol}^{-1})$ for $\text{CH}_3\text{COOH}$ will be: