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An electric heater having heating coil of 484 ω connected with a supply voltage of 220 v is used to heat water. The time taken to increase the temperature of 100 g water by 50ºc is

An electric heater having a heating coil of 150 ohms connected with a supply voltage of 220 V is used to heat water. The time taken to increase... View Article

A laser beam of a plane monochromatic radiation has intensity 20 1014 wm2 the amplitude of magnetic field in this beam is

A laser beam of a plane monochromatic radiation has an intensity of 2.5 × 10^14 Wm−2. The amplitude of the magnetic field in this beam is... View Article

If equation of sound wave is y 00015 sin 624 x 316 t then its wavelength will be

If the equation of sound wave is y = 0.0015sin(62.4x + 316t), then its wavelength will be Answer: If the equation of the sound wave is y =... View Article

The half-life of [latex]_{238}^{92}textrm{U}[/latex] undergoing α-decay is 4.5 * 10^-9. What is the true activity initial of 1 gm of the sample?

The half-life of undergoing α-decay is 4.5 * 10-9. What is the true activity initial 1 gm of the sample? Answer: The true activity of the... View Article

A car is moving on a circular track of radius of 150 m, and at some time, its speed is decreasing at a rate of 8 ms². If the speed of the car at that instant was 30 m/s, then the net acceleration of the car will be

A car is moving on a circular track of radius of 150 m, and at some time, its speed is decreasing at a rate of 8 ms2. If the speed of the car at... View Article

A balloon of weight w newton descends with an acceleration f m/s2 the weight that must be thrown out in order to give equal upward acceleration to the balloon will be

A balloon of weight w newton descends with an acceleration f m/s2. The weight that must be thrown out in order to give equal upward acceleration... View Article

A charge q is moving with a velocity opposite to the direction of magnetic field force on the charge due to the magnetic field is

A charge q is moving with a velocity opposite to the direction of magnetic field force on the charge due to the magnetic field is (a) 0 (b) qB/v... View Article

Two stones having different masses m1 and m2 are projected at angles θ and (90 – θ) with the same speed from the same point. The ratio of their maximum heights is

Two stones having different masses m1 and m2 are projected at angles θ and (90 - θ) with the same speed from the same point. The ratio of their... View Article

The blades of an aeroplane are rotating at the rate of 600 revolution per minute the angular velocity of blades is

The blades of an aeroplane are rotating at the rate of 600 revolutions per minute the angular velocity of blades is (a) π rad/s (b) 2π rad/s (c)... View Article

Two inductors of inductance l each are connected in series with opposite? magnetic fluxes the resultant inductance is

Two inductors of inductance l each are connected in series with the opposite magnetic fluxes, the resultant inductance is (a) 0 (b) L (c) 2L (d)... View Article

Two plane mirrors are inclined at angle θ if any ray incident on one mirror becomes anti-parallel after reflection from other mirror then angle θ can be

Two plane mirrors are inclined at an angle theta. If any ray incident on one mirror becomes anti-parallel after reflection from another mirror... View Article

An open pipe of length 33 cm resonates with frequency of 750 hz if the speed of the sound is 330 m/s then this frequency is

An open pipe of length 33 cm resonates with frequency of 750 hz if the speed of the sound is 330 m/s then this frequency is 1.the first harmonic... View Article

Two coils have a mutual inductance of 0.01 H. The current changes in the first coil according to the equation I = 5sin 200πt. What is the maximum value of emf induced in the second coil?

Π V 10π V 0.1π V 0.01 π V Answer: 10π V... View Article

The momentum of a body in two perpendicular direction at any time t are given by px 2t2 4 n s and py 3t2 6 n s the force acting on the body at t 0 will be

The momentum of a body in two perpendicular direction at any time t are given by Px = 2t2 + 6 and Py = 3t2/2 + 3. The force acting on the... View Article

An ideal heat engine operates between 227c and 127c it absorbs 5 kcal of heat at higher temperature what is heat rejected to sink?

An ideal heat engine operates between 227°C and 127°C. It absorbs 5 kcal of heat at higher temperatures. What is the heat rejected to sink? (a) 3... View Article

A charge q is moved from a to c along the path abc as shown in figure the work done in moving charge from a to c is

A charge q is moved from A to C along with the path ABC as shown in the figure the work done in moving charge from A to C is Answer: The work... View Article

If resistance of voltmeter is 40 ω then error in reading of voltmeter is 5n find the value of n

In the given circuit, the resistance of the circuit is 4kΩ, then the error in the reading of the voltmeter wil be (a) 68 % (b) 33.3 % (c) 50 %... View Article

A galvanometer has resistance of 63 ω in order to send only 10 of main current through this galvanometer the resistance of required shunt is

A galvanometer has resistance of 900 ohms. In order to send only 10 % of main current through this galvanometer the resistance of required shunt... View Article

In the circuit diagram the input is across the terminal a and c and the output is across b and d then output is

In the circuit diagram the input is across the terminal a and c and the output is across b and d then output is (a) same as input (b) zero (c)... View Article

The primary winding of an ideal transformer has 1000 turns whereas its secondary has 5000 turns the primary is connected to an ac supply of 220 v 50 hz the secondary will have an output of

The primary winding of an ideal transformer has 1000 turns whereas its secondary has 5000 turns. The primary is connected to an a supply of 220 V... View Article